PIC 16F628 Frequency Counter with RS232 output in a DB9 backshell by Jan Panteltje

by Jan Panteltje

From: http://panteltje.com/panteltje/pic/freq_pic/

Very nice "Dead Bug" Construction!

;************************************************************************** ; FILE: counter.asm * ; CONTENTS: Simple low-cost digital frequency meter using a PIC 16F628 * ; AUTHOR: Wolfgang Buescher, DL4YHF * ; (based on a work by James Hutchby, MadLab, 1996) * ; REVISIONS: (latest entry first) * ; 2009-08-27 - Added RS232 output option 1200 Bd by Jan Panteltje * ; 2006-05-31 - Added the 'power-save' option which temporarily puts the * ; PIC to sleep (with only the watchdog-oscillator running) * ; 2006-05-15 - New entry in the preconfigured frequency table for 4-MHz * ; IF filters (like "Miss Mosquita" [Moskita] by DK1HE) * ; 2005-08-24 - Cured a bug in the COMMON ANODE decimal point setting . * ; (the "^0xFF" for the AND-mask was missing in macro 'conv') * ; 2005-03-21 - Added a few conditionals to use the same sourcecode * ; to drive a COMMON ANODE display ( DISPLAY_VARIANT_3 ) * ; 2004-03-14 - Fixed a range-switching bug around 8 MHz . * ; - Support TWO different display variants now, * ; optimized for different board layouts, and different clock * ; frequencies (4 MHz for variant 1, 20 MHz for variant 2). * ; 2004-03-05 - Added the feature to add or subtract a frequency offset . * ; 2004-02-18 - Migration to a PIC16F628 with 4 MHz crystal (el Cheapo) * ; - Changed the LED patterns '6' and '9' because they looked * ; like 'b' and 'q' in the old counter version . * ; - Added the auto-ranging feature * ; - Stepped from 24-bit to 32-bit integer arithmetic, to be * ; able to count 50 MHz with 1-second gate time, * ; or (at least) adjust ANY result for the ANY prescaler * ; division ratio, which may give pretty large numbers . * ; - A PIC16F628 worked up to 63 MHz with this firmware . * ;************************************************************************** list P=16F648a ; #include <p16F628.inc> ; processor specific definitions #include <p16f648a.inc> ; processor specific definitions ; Uncomment this if you want RS232 output #define RS232_OUT ; Uncomment the next line if you want pin 8 of the PIC to directly drive a RS232 line (without MAX232 or such). #define NON_INVERTING_RS232_OUT ; BAUD_DIVIDER set to 1 for 9600 Bd, 2 for 4800 Bd, 4 for 2400 Bd, 8 for 1200 Bd, 16 for 600 Bd, 32 for 300 Bd, 64 for 150 Bd, and 128 for 75 Bd. ; Note: for 9600 Bd set BIT_DELAY to 27, or basically a bit lower then for the other baudrates, due to more relative time spend in other instructions. #define BAUD_DIVIDER d'8' ; 1200 Baud ; set baudrate, for small deviations of the internal oscillator this may need to be adapted. #define BIT_DELAY d'165' ; approx 165 for 1200 Bd with 20 MHz clock ; for software RS232 out, NOT using UART #define RS232_PORT PORTB #define RS232_BIT D'2' ; RB2, pin 8 ; print options, all field active looks like: ; 00000050 50 Hz 0.050 kHz ; 19999968 19,999,968 Hz 19.999 MHz ; Uncomment this if you want the first field printed. #define RS232_PRINT_FIELD_1 ; Uncomment this if you want the secind field printed. #define RS232_PRINT_FIELD_2 ; Uncomment this if you want the third field printed. ;#define RS232_PRINT_FIELD_3 ; Note: The first field is for parsing by user space programs. it is recommanded to always leave the field active. ; for unit printing #define KILOHERTZ_FLAG 1 #define NO_INPUT_FLAG 2 #define ZERO_SUPPRESSION_FLAG 4 #define DISPLAY_VARIANT_2 #define DEBUG 0 ; DEBUG=1 for simulation, DEBUG=0 for real hardware ; Selection of LED display control bits... since 2005, three different variants. ; Select ONE OF THESE in MPLAB under "Project".."Build Options".."Macro Definitions"! ; DISP_VARIANT=1 : first prototype, PIC on left side of display ; DISP_VARIANT=2 : second prototype, separated PIC and display board ; DISP_VARIANT=3 : similar as (2), but for COMMON CATHODE display ; Unfortunately it seems impossible to assign a NUMERIC VALUE to a macro ; in MPLAB (not in MPASM!) .... #ifdef DISPLAY_VARIANT_1 #define DISP_VARIANT 1 ; very first (old) prototype by DL4YHF #define COMMON_ANODE 0 #define COMMON_CATHODE 1 #else #ifdef DISPLAY_VARIANT_2 #define DISP_VARIANT 2 ; 5 digits, new layout, COMMON CATHODE #define COMMON_ANODE 0 #define COMMON_CATHODE 1 #else #ifdef DISPLAY_VARIANT_3 ; added 2005-03-21 : #define DISP_VARIANT 3 ; similar as (2), but for COMMON ANODE display #define COMMON_ANODE 1 #define COMMON_CATHODE 0 #else #define DISP_VARIANT 4 #define COMMON_ANODE 0 #define COMMON_CATHODE 1 ; "Error, Must define DISPLAY_VARIANT_1, .._2, or .._3 under project options" ; With MPLAB: Project..Build Options..Project..MPASM..Macro Definitions..Add #endif #endif #endif ;************************************************************************** ; * ; Summary * ; * ;************************************************************************** ; The software functions as a frequency meter with an input signal ; range of 1 Hz to ~ 50 MHz and with an accuracy of +/- 1Hz ; if the oscillator crystal is properly trimmed . ; Signal pulses are counted over a fixed time interval of 1/4 second to ; 1 second (gate time). High frequency pulses are counted over 1/4 s ; to make the meter more responsive with no loss of displayed accuracy. ; Pulses are counted using Timer 0 of the PIC, ; which is set to increment on rising edges on the TMR0 pin. The 8-bit ; hardware register is extended by software into a 32-bit pulse counter. ; If timer 0 rolls over (msb 1 -> 0) between successive polls then the ; high two bytes of the pulse counter are incremented. ; Timer 0 is unable to count more than one pulse per instruction cycle ; (per 4 clock cycles) so the prescaler is used at frequencies above ; 1MHz (4MHz clock / 4) and also to ensure that pulses are not lost ; between polls of timer 0 (which would happen if more than 128 pulses were ; received). Fortunately the prescaler is an asynchronous counter ; which works up to a few ten MHz (sometimes as far as 60 MHz) . ; Timing is based on a software loop of known execution period . The loop ; time is 50 or 20 us which gives integer counts to time 1 s and 1/4 s . ; During this timing loop, the multiplexed LED display is updated . ; The frequency in binary is converted to decimal using a powers-of-ten ; lookup table. The binary powers of ten are repeatedly subtracted from ; the frequency to determine the individual decimal digits. The decimal ; digits are stored at the 8 bytes at 'digits'. Leading zeroes are then ; suppressed and the 4 (or 5) significant digits are converted to LED data ; for the 7-segment displays using a lookup table. ; The signal frequency is displayed on four (or five) 7-segment displays. ; The displays are multiplexed which means that only one display is enabled ; at any one time. The variable 'disp_index' contains the index of the currently ; enabled display. Each display is enabled in turn at a sufficient frequency ; that no flicker is discernable. A prescaler ('disp_timer') is used ; to set the multiplexing frequency to a few hundred Hz. ; The display shows the signal frequency in KHz or MHz, according to the ; following table: ; -------------------------- ; | Frequency | Display | ; -------------------------- ; | < 1Hz | 0 | ; | 1Hz | 0.001[0] | Note: kHz-dot is flashing (blinking) ; | 10Hz | 0.010[0] | ; | 100Hz | 0.100[0] | ; | 1.000KHz | 1.000[0] | ; | 10.00KHz | 10.00[0] | ; | 100.0KHz | 100.0[0] | ; | 1.000MHz | 1.000[0] | Note: MHz-dot is steady (not blinking) ; | 10.00MHz | 10.00[0] | ; -------------------------- ; If there is no signal at all, a single zero is displayed in the 4th(!) digit. ; Overflows are not displayed because they cannot be detected ! ;************************************************************************** ; * ; PIC config definitions * ; * ;************************************************************************** ; '__CONFIG' directive is used to embed configuration data within .asm file. ; The lables following the directive are located in the respective .inc file. ; See respective data sheet for additional information on configuration word. ; Since 2006-05-28, the watchdog must be ENABLE in the config word ; because of its wakeup-from-sleep function (see 'Sleep100ms') . ; EX(16F84:) __CONFIG _CP_OFF &amp _WDT_ON & _PWRTE_ON &amp _RC_OSC #if (DISP_VARIANT==1) ; display variant 1 : clocked with 4 MHz (low power, "XT" ) __CONFIG _CP_OFF & _WDT_ON & _PWRTE_ON & _XT_OSC & _LVP_OFF & _BODEN_OFF & _MCLRE_OFF #else ; display variants 2+3 : clocked with 20 MHz (needs "HS" oscillator) __CONFIG _CP_OFF & _WDT_ON & _PWRTE_ON & _HS_OSC & _LVP_OFF & _BODEN_OFF & _MCLRE_OFF #endif ; '__IDLOCS' directive may be used to set the 4 * 4(?!?) ID Location Bits . ; These shall be placed in the HEX file at addresses 0x2000...0x2003 . __IDLOCS H'1234' ; (definitions of "file" registers removed. They are defined in a header file!) ;************************************************************************** ; * ; Port assignments * ; * ;************************************************************************** PORT_A_IO equ b'0000' ; port A I/O mode (all output) PORT_B_IO equ b'00000000' ; port B I/O mode (all output) LEDS_PORT equ PORTB ; 7-segment LEDs port ENABLE_PORT equ PORTA ; display enable port ; Bitmasks to control the digit outputs have been moved to enable_table . ; YHF: Note that 'display #0' is the MOST SIGNIFICANT digit ! #define IOP_PROG_MODE PORTA,5 ; digital input signal, LOW enters programming mode ;************************************************************************** ; * ; Constants and timings * ; * ;************************************************************************** ; processor clock frequency in Hz (4MHz) #if (DISP_VARIANT==1) ; display variant 1 : clocked with 4 MHz (low power consumption) CLOCK equ .4000000 #else ; display variants 2+3 : clocked with 20 MHz (higher resolution) CLOCK equ .20000000 #endif ; microseconds per timing loop #if (DISP_VARIANT==1) ; display variant 1 : clocked with 4 MHz ; 20 microseconds is impossible with 4-MHz-Crystal, so use 50 us instead ! ; Make sure all gate times can be divided by this interval without remainder : ; 1 second / 50 us = 20000 (ok) ; 1/4 second / 50 us = 5000 (ok) ; 1/8 second / 50 us = 2500 (ok) TIME equ .50 #else ; display variants 2+3 : clocked with 20 MHz ; 20 microseconds is impossible with 4-MHz-Crystal, so use 50 us instead ! ; Make sure all gate times can be divided by this interval without remainder : ; 1 second / 20 us = 50000 (ok) ; 1/4 second / 20 us = 12500 (ok) ; 1/8 second / 50 us = 6250 (ok) TIME equ .20 #endif ; variant 1 or 2+3 ? ; Clock cycles per timing loop. See subroutine count_pulses . ; Usually CYCLES=200 (for 4 MHz crystal, 50 usec - loop) ; or 400 (for 20 MHz crystal, 20 usec - loop) CYCLES equ TIME*CLOCK/.1000000 GATE_TIME_LOOPS equ CLOCK/CYCLES ; number of gate-time loops for ONE SECOND gate time LAMPTEST_LOOPS equ CLOCK/(.2*CYCLES) ; number of loops for a 0.5 SECOND lamp test after power-on PROGMODE_LOOPS equ CLOCK/(.10*CYCLES) ; number of delay loops for display in PROGRAMMING MODE (0.1 sec) ; Configuration of power-saving mode : #if( DEBUG ) PSAVE_DELAY_TIME equ .10 ; number of 0.25-sec-intervals before turning off (shorter for debugging) #else PSAVE_DELAY_TIME equ .60 ; number of 0.25-sec-intervals before turning off (some dozen seconds) #endif PSAVE_FLASHUP_TIME equ .14 ; number of 0.7(!)-second-intervals between two flashes in power-saving mode PSAVE_MAX_DIFF equ .10 ; maximum frequency difference (range-dependent, see below) ; Unit: N times "frequency-resolution", see frequency-range table . ; Example: PSAVE_MAX_DIFF=10 means 10*4Hz in Range 1 (1..3.4 MHz) . ; Menu Indices ... must match the jump table PMDisplay + PMExecute ! MI_QUIT equ 0 ; exit from menu MI_PSAVE equ 1 ; turn "power save"-option on and off MI_ADD equ 2 ; save frequency offset to ADD it from now on MI_SUB equ 3 ; save frequency offset to SUBTRACT it from now on MI_ZERO equ 4 ; set the frequency offset to ZERO and leave menu MI_STD_IF equ 5 ; jump into the STANDARD INTERMEDIATE FREQUENCY table.. MI_INDEX_MAX equ 5 ; normal menu indices up to MI_INDEX_MAX . MI_IF_1 equ 6 ; show the 1st standard IF MI_IF_2 equ 7 ; show the 2nd standard IF MI_IF_3 equ 8 ; show the 3rd standard IF MI_IF_4 equ 9 ; show the 4th standard IF MI_IF_5 equ 0x0A ; show the 4th standard IF MI_IF_QT equ 0x0B ; exit standard IF menu without changing anything MI_IF_SUBMENU_MAX equ 0x0A ;************************************************************************** ; * ; File register usage * ; * ;************************************************************************** ; RAM memory (general purpose registers, unfortunately not the same for PIC16F84 & PIC16F628) ; in PIC16F628: RAM from 0x20..0x7F (96 bytes, 0x20.. only accessable in Bank0) ; 0xA0..0xEF (another 80 bytes in Bank1) ; 0x120..0x14F (another 48 bytes in Bank2) ; 0x0F0..0x0FF, 0x170..0x17F , 0x1F0..0x1FF are mapped to 0x70..0x7F (same in all banks) ; So use 0x70..0x7F for context saving in the PIC16F628 and forget 0x0F0.. 0xNNN ! ; ; Note on the 32-bit integer arithmetics as used in this code: ; - They begin with MOST SIGNIFICANT BYTE in memory, but... ; - Every byte location has its own label here, which makes debugging ; with Microchip's simulator much easier (point the mouse on the name ; of a variable to see what I mean !) ; tens_index equ 0x27 ; index into the powers-of-ten table divi equ 0x28 ; power of ten (32 bits) divi_hi equ 0x28 ; same as 'divi' : HIGH byte divi_mh equ 0x29 ; MEDIUM HIGH byte divi_ml equ 0x2A ; MEDIUM LOW byte divi_lo equ 0x2B ; LOW byte timer0_old equ 0x2C ; previous reading from timer0 register gatecnt_hi equ 0x2D ; 16-bit counter (msb first) gatecnt_lo equ 0x2E ; 16-bit counter (lsb last) bTemp equ 0x2F ; temporary 8-bit register, ; may be overwritten in ALL subroutines freq equ 0x30 ; frequency in binary (32 bits).... freq_hi equ 0x30 ; same location, begins with HIGH byte freq_mh equ 0x31 ; ... medium high byte freq_ml equ 0x32 ; ... medium low byte freq_lo equ 0x33 ; ... low byte freq2 equ 0x34 ; frequency too, copied for programming mode freq2_hi equ 0x34 ; same location, begins with HIGH byte freq2_mh equ 0x35 ; ... medium high byte freq2_ml equ 0x36 ; ... medium low byte freq2_lo equ 0x37 ; ... low byte foffs equ 0x38 ; frequency too, copied for programming mode foffs_hi equ 0x38 ; same location, begins with HIGH byte foffs_mh equ 0x39 ; ... medium high byte foffs_ml equ 0x3A ; ... medium low byte foffs_lo equ 0x3B ; ... low byte menu_index equ 0x3C ; menu item for programming mode menu_timer equ 0x3D ; used to detect how long a key was pressed digits equ 0x40 ; frequency as decimal digits (8 bytes)... digit_0 equ 0x40 ; same location as MOST SIGNIFICANT digit, 10-MHz digit_1 equ 0x41 ; usually the 1-MHz-digit digit_2 equ 0x42 ; usually the 100-kHz-digit digit_3 equ 0x43 ; usually the 10-kHz-digit digit_4 equ 0x44 ; usually the 1-kHz-digit digit_5 equ 0x45 ; usually the 100-Hz-digit digit_6 equ 0x46 ; usually the 10-Hz-digit digit_7 equ 0x47 ; usually the 1-Hz-digit digit_8 equ 0x48 ; must contain a blank character (or trailing zero) display0 equ 0x49 ; display #0 data display1 equ 0x4A ; display #1 data display2 equ 0x4B ; display #2 data display3 equ 0x4C ; display #3 data display4 equ 0x4D ; display #4 data disp_index equ 0x4E ; index of the enabled display (0 to 4 for 5-digit display) disp_timer equ 0x4F ; display multiplex timer (5 bits) adjust_shifts equ 0x50 ; count of 'left shifts' to compensate prescaler+gate time blinker equ 0x51 ; prescaler for the flashing 1-kHz-dot psave_timer equ 0x52 ; timer for power-save mode (incremented every 0.25 seconds) psave_freq_lo equ 0x53 ; low-byte of frequency to detect changes for power-save mode psave_flags equ 0x54 ; power-saving flags with the following bits: #define PSFLAG_ACTIVE psave_flags,0 ; clear:normal mode, set:power-saving in action (display blanked) options equ 0x55 ; display options with the following flag-bits: #define OPT_PWRSAVE options,0 ; clear:normal mode, set:power-saving mode enabled tx_reg equ 0x56 bit_count equ 0x57 baud_divider equ 0x58 delay_counter equ 0x59 print_flags equ 0x5A temp equ 0x5B ;************************************************************************** ; * ; Macros (1) * ; * ;************************************************************************** eep_dw macro value ; a DOUBLEWORD split into 4 bytes in the PIC's DATA EEPROM de (value>>.24), (value>>.16)&0xFF, (value>>8)&0xFF, value&0xFF endm ;************************************************************************** ; * ; EEPROM memory definitions * ; * ;************************************************************************** ; for PIC16F84: 0x00..0x3F were valid EEPROM locations (64 byte) ; for PIC16F628: 0x00..0x7F are valid EEPROM locations (128 byte) #define EEPROM_ADR_FREQ_OFFSET 0x00 ; EEPROM location for frequency offset #define EEPROM_ADR_STD_IF_TABLE 0x04 ; EEPROM location for standard IF table (4*4 byte) #define EEPROM_ADR_OPTIONS 0x20 ; EEPROM location for "options" (flags) ; This gives warnings with gpasm 'Warning [220] Address exceeds maximum range for this processor.' ; Initial contents of DATA EEPROM: org (0x2100+EEPROM_ADR_FREQ_OFFSET) eep_dw .0 ; [00..03] initial frequency offset = ZERO org (0x2100+EEPROM_ADR_STD_IF_TABLE) ; standard IF table ... eep_dw .455000 ; [04..07] frequently used in old AM radios eep_dw .3999000 ; [08..0B] used in "Miss Mosquita" (DK1HE / DL QRP AG) eep_dw .4194304 ; [0C..0F] used in other homebrew amateur radio receivers eep_dw .4433619 ; [10..13] sometimes used in homebrew amateur radio receivers eep_dw .10700000 ; [14..17] frequently used in old FM radios ; [18..1F] reserved for other "preprogrammed" values org (0x2100+EEPROM_ADR_OPTIONS) de .0 ; [20] "options" (flags), cleared by default ;************************************************************************** ; * ; More Macros * ; * ;************************************************************************** ;-------------------------------------------------------------------------- ; macros to implement lookup tables - these macros hide the PIC syntax ; used and make the source code more readable ; (YHF: CAUTION - BUT THESE MACROS HIDE SOME VERY NASTY PITFALLS . ; TABLE MUST NOT CROSS PAGE BORDER DUE TO 'ADDWF PCL, f' ! ) ;-------------------------------------------------------------------------- cquad macro value retlw value>>.24 ; high byte retlw (value>>.16)&0xFF ; middle-high byte retlw (value>>8)&0xFF ; middle-low byte retlw value&0xFF ; low byte endm table macro label ; define lookup table label addwf PCL,f ; caution: this is 'PCL' only, cannot add to the full 'PC' in a PIC ! endm ;-------------------------------------------------------------------------- ; add with carry - adds the w register and the carry flag to the file ; register reg, returns the result in <reg> with the carry flag set if overflow ;-------------------------------------------------------------------------- addcwf macro reg local add1,add2 bnc add1 ; branch if no carry set addwf reg , f ; add byte incf reg , f ; add carry skpnz setc goto add2 add1 addwf reg,f ; add byte add2 endm ;-------------------------------------------------------------------------- ; subtract with "no-carry" - subtracts the w register and the no-carry flag ; from the file register reg, returns the result in reg with the no carry flag ; set if underflow ;-------------------------------------------------------------------------- subncwf macro reg local sub1,sub2 bc sub1 ; branch if carry set subwf reg, f ; subtract byte skpnz ; subtract no carry clrc decf reg , f goto sub2 sub1 subwf reg , f ; subtract byte sub2 endm ;-------------------------------------------------------------------------- ; MACRO to perform 32-bit addition - adds the four bytes at op2 to the ; three bytes at op1 (most significant bytes first), returns the result in ; op1 with op2 unchanged and the carry flag set if overflow ;-------------------------------------------------------------------------- add32 macro op1,op2 ; op1 := op1 + op2 movfw op2+3 ; add low byte (bits 7...0) addwf op1+3,f movfw op2+2 ; add middle-low byte (bits 15..8) addcwf op1+2 movfw op2+1 ; add middle-high byte (bits 23...16) addcwf op1+1 movfw op2+0 ; add high byte (bits 31...24) addcwf op1+0 endm ;-------------------------------------------------------------------------- ; MACRO to perform 32-bit subtraction - subtracts the four bytes at op2 ; from the four bytes at op1 (most significant bytes first), returns the ; result in op1 with op2 unchanged and the no carry flag set if underflow ;-------------------------------------------------------------------------- sub32 macro op1,op2 ; op1 := op1 - op2 movfw op2+3 ; subtract low byte subwf op1+3 , f movfw op2+2 ; subtract middle low byte subncwf op1+2 movfw op2+1 ; subtract middle high byte subncwf op1+1 movfw op2+0 ; subtract high byte subncwf op1+0 endm ;-------------------------------------------------------------------------- ; MACRO to negate a 32-bit value ( op := 0 - op ) . ;-------------------------------------------------------------------------- neg32 macro op ; op1 := 0 - op2 local neg_done comf op, f ; invert all 8 bits in high byte comf op+1, f ; invert all 8 bits in middle high byte comf op+2, f ; invert all 8 bits in middle low byte comf op+3, f ; invert all 8 bits in low byte ; Note at this point 0x000000 would have turned into 0xFFFFFFF . ; Must add ONE to complete the TWO's COMPLIMENT calculation ( -0 = 0 ). ; Note that "incf" affects only the Z flag but not the C flag . incfsz op+3, f ; increment low byte (bits 7...0) goto neg_done ; if incremented result NOT zero, we're through ! incfsz op+2, f ; increment middle low byte (bits 15...8) goto neg_done ; if incremented result NOT zero, ... incfsz op+1, f ; increment middle high byte (bits 23...16) goto neg_done ; if ... incfsz op+0, f ; increment high byte (bits 31...24) goto neg_done ; neg_done endm ;********************************************************************** ORG 0x000 ; processor reset vector goto MainInit ; go to beginning of program ; (begin of ROM is too precious to waste for ordinary code, see below...) ;************************************************************************** ; * ; Lookup tables * ; Must be at the start of the code memory to avoid crossing pages !! * ; * ;************************************************************************** ;-------------------------------------------------------------------------- ; 7-segment LED data table ;-------------------------------------------------------------------------- ; Index 0..9 used for decimal numbers, all other indices defined below : CHAR_A equ .10 ; Letters A..F = HEX digits, index 10..15 CHAR_b equ .11 ; CHAR_c equ .12 ; CHAR_d equ .13 ; CHAR_E equ .14 ; CHAR_F equ .15 ; CHAR_G equ .16 ; Other letters used in "programming" mode CHAR_H equ .17 ; CHAR_i equ .18 ; BLANK equ .19 ; blank display TEST equ .20 ; power-on display test CHAR_P equ .21 ; A few other letters for programming mode... CHAR_r equ .22 ; CHAR_o equ .23 ; "Prog" CHAR_Q equ .24 ; "Quit" CHAR_u equ .25 ; CHAR_t equ .26 ; CHAR_S equ .27 ; "Sub" CHAR_Z equ .28 ; "ZEro" CHAR_I equ .29 ; large "I" (left aligned!) for "IF" CHAR_J equ .30 ; CHAR_k equ .31 ; CHAR_L equ .32 ; CHAR_N equ .33 ; CHAR_V equ .34 ; CHAR_EQ equ .35 ; "=" #if (DISP_VARIANT==1) DPPOINT_BIT equ 4 ; decimal point bit (same for all digits) #define _A 0x01 ; bitmask for segment A , etc .. #define _B 0x02 #define _C 0x20 #define _D 0x08 #define _E 0x04 #define _F 0x40 #define _G 0x80 #define _DP 0x10 #endif ; DISPLAY VARIANT #1 #if (DISP_VARIANT==2) || (DISP_VARIANT==3) DPPOINT_BIT equ 1 ; decimal point bit (same for all digits) #define _A 0x40 ; bitmask for segment A , etc .. #define _B 0x80 #define _C 0x04 #define _D 0x01 #define _E 0x08 #define _F 0x10 #define _G 0x20 #define _DP 0x02 #endif ; DISPLAY VARIANT #2 + #3 BLANK_PATTERN equ b'00000000' ; blank display pattern (7-segment code) ;----------------------------------------------------------------------------- ; Table to convert a decimal digit or a special character into 7-segment-code ; Note: In DL4YHF's PIC counter, all digits have the same segment connections, ; so we do not need individual conversion tables for all segments. ; ; AAAA ; F B ; F B ; GGGG ; E C ; E C ; DDDD DP ; ;----------------------------------------------------------------------------- Digit2SevenSeg: addwf PCL,f ; caution: this is 'PCL' only, not 'PC'. Beware of page borders. ; A = 0, B = 1, C = 5, D = 3, E = 2, F = 6, G = 7, DP = 4 #if (COMMON_ANODE) #define SSEG_XORMASK 0xFF ; since 2005-03-21 ... never tested by the author ! #else #define SSEG_XORMASK 0x00 ; for COMMON CATHODE: No bitwise EXOR to the pattern #endif retlw (_A+_B+_C+_D+_E+_F )^SSEG_XORMASK ; ABCDEF. = '0' ( # 0 ) retlw ( _B+_C )^SSEG_XORMASK ; .BC.... = '1' ( # 1 ) retlw (_A+_B +_D+_E +_G)^SSEG_XORMASK ; AB.DE.G = '2' ( # 2 ) retlw (_A+_B+_C+_D +_G)^SSEG_XORMASK ; ABCD..G = '3' ( # 3 ) retlw ( _B+_C +_F+_G)^SSEG_XORMASK ; .BC..FG = '4' ( # 4 ) retlw (_A +_C+_D +_F+_G)^SSEG_XORMASK ; A.CD.FG = '5' ( # 5 ) retlw (_A +_C+_D+_E+_F+_G)^SSEG_XORMASK ; A.CDEFG = '6' ( # 6 ) retlw (_A+_B+_C )^SSEG_XORMASK ; ABC.... = '7' ( # 7 ) retlw (_A+_B+_C+_D+_E+_F+_G)^SSEG_XORMASK ; ABCDEFG = '8' ( # 8 ) retlw (_A+_B+_C+_D +_F+_G)^SSEG_XORMASK ; ABCD.FG = '9' ( # 9 ) retlw (_A+_B+_C +_E+_F+_G)^SSEG_XORMASK ; ABC.EFG = 'A' ( # 10 ) retlw ( _C+_D+_E+_F+_G)^SSEG_XORMASK ; ..CDEFG = 'b' ( # 11 ) retlw ( _D+_E +_G)^SSEG_XORMASK ; ...DE.G = 'c' ( # 12 ) retlw ( _B+_C+_D+_E +_G)^SSEG_XORMASK ; .BCDE.G = 'd' ( # 13 ) retlw (_A +_D+_E+_F+_G)^SSEG_XORMASK ; A..DEFG = 'E' ( # 14 ) retlw (_A +_E+_F+_G)^SSEG_XORMASK ; A...EFG = 'F' ( # 15 ) retlw (_A +_C+_D+_E+_F )^SSEG_XORMASK ; A.CDEF. = 'G' ( # 16 ) retlw ( _B+_C +_E+_F+_G)^SSEG_XORMASK ; .BC.EFG = 'H' ( # 17 ) retlw ( _E )^SSEG_XORMASK ; ....E.. = 'i' ( # 18 ) retlw (BLANK_PATTERN )^SSEG_XORMASK ; ....... = ' ' ( # 19 ) retlw (b'11111111' )^SSEG_XORMASK ; all segments on ( # 20 ) ; A few more letters for programming mode : retlw (_A+_B +_E+_F+_G)^SSEG_XORMASK ; AB..EFG = 'P' ( # 21 ) retlw ( _E +_G)^SSEG_XORMASK ; ....E.G = 'r' ( # 22 ) retlw ( _C+_D+_E +_G)^SSEG_XORMASK ; ..CDE.G = 'o' ( # 23 ) retlw (_A+_B+_C +_F+_G)^SSEG_XORMASK ; ABC..FG = 'Q' ( # 24 ) retlw ( _C+_D+_E )^SSEG_XORMASK ; ..CDE.. = 'u' ( # 25 ) retlw ( _D+_E+_F+_G)^SSEG_XORMASK ; ...DEFG = 't' ( # 26 ) retlw (_A +_C+_D +_F+_G)^SSEG_XORMASK ; A.CD.FG = 'S' ( # 27 ) retlw (_A+_B +_D+_E +_G)^SSEG_XORMASK ; AB.DE.G = 'Z' ( # 28 ) retlw ( _E+_F )^SSEG_XORMASK ; ....EF. = 'I' ( # 29 ) retlw ( _B+_C+_D )^SSEG_XORMASK ; .BCD.. = 'J' ( # 30 ) retlw ( _D+_E+_F+_G)^SSEG_XORMASK ; ...DEFG = 'k' ( # 31 ) retlw ( _D+_E+_F )^SSEG_XORMASK ; ...DEF. = 'L' ( # 32 ) retlw (_A+_B+_C +_E+_F )^SSEG_XORMASK ; ABC.EF. = 'N' ( # 33 ) retlw ( _C+_D+_E+_F )^SSEG_XORMASK ; ..CDEF. = 'V' ( # 34 ) retlw ( _D +_G)^SSEG_XORMASK ; ...D..G = '=' ( # 35 ) ;-------------------------------------------------------------------------- ; Table to control which 7-segment display is enabled. Displays are usually ; COMMON CATHODE (variants 1+2) so pulled low to enable. ; For DISP_VARIANT=3 (COMMON ANODE), the digit-driving pattern is inverted. ; Input: W = 0 means the MOST SIGNIFICANT DIGIT (the leftmost one), etc. ; Result: VALUE to be written to ENABLE_PORT to activate the digit ;-------------------------------------------------------------------------- Digit2MuxValue: ; addwf PCL,f ; caution: this is 'PCL' only, not 'PC' ; Note: If the program counter is affected, a command requires to instruction cycles (=8 osc cycles) #if (DISP_VARIANT==1) ; muliplexer values for DISPLAY VARIANT #1 : retlw b'11110111' ; most significant digit is on PA3 (!) retlw b'11111110' ; next less significant dig. on PA0 (!) retlw b'11111011' ; next less significant dig. on PA2 (!) retlw b'11111101' ; 4th (sometimes the last) digit PA1 (!) retlw b'11111111' ; 5th (OPTIONAL) least significant digit = NOT (PA3+PA2+PA1+PA0) #endif ; DISPLAY VARIANT #1 #if (DISP_VARIANT==2) ; muliplexer values for DISPLAY VARIANT #2 (5 digits, COMMON CATHODE) : retlw b'11110111' ; most significant digit is on PA3 (!) retlw b'11111011' ; next less significant dig. on PA2 (!!) retlw b'11111110' ; next less significant dig. on PA0 (!!) retlw b'11111101' ; 4th (sometimes the last) digit PA1 (!) retlw b'11111111' ; 5th (OPTIONAL) least significant digit = NOT (PA3+PA2+PA1+PA0) #endif ; DISPLAY VARIANT #2 #if (DISP_VARIANT==3) ; muliplexer values for DISPLAY VARIANT #3 (5 digits, COMMON ANODE) : ; Unused bits (b7..b4) are left HIGH as above . retlw b'11111000' ; most significant digit is on PA3 (!) retlw b'11110100' ; next less significant dig. on PA2 (!!) retlw b'11110001' ; next less significant dig. on PA0 (!!) retlw b'11110010' ; 4th (sometimes the last) digit PA1 (!) retlw b'11110000' ; 5th (OPTIONAL) least significant digit = NOT (PA3+PA2+PA1+PA0) #endif ; DISPLAY VARIANT #2 ;-------------------------------------------------------------------------- ; Powers-of-ten table (32 bits, most significant byte first) ; Based on an idea by James Hutchby (MadLab, 1996) . ; Modified for 32-bit arithmetic by Wolfgang Buescher (2004). ;-------------------------------------------------------------------------- TensTable addwf PCL,f cquad .10000000 ; 10 million is sufficient for the counter itself cquad .1000000 cquad .100000 cquad .10000 cquad .1000 cquad .100 cquad .10 cquad .1 ;-------------------------------------------------------------------------- ; DISPLAY jump table for programming mode . ; Loads the display-strings like "quit" etc into the display latches. ; Input parameter: menu_index (0 .. MI_INDEX_MAX) ; Output placed in display0..display3 ; ;-------------------------------------------------------------------------- PMDisplay: movfw menu_index ; load menu index into W register addwf PCL, f ; add W to lower part of program counter (computed jump) goto PmDisp_Quit ; show "quit" (quit programming mode) goto PmDisp_PSave; show "PSave"(power-saving mode on/off) goto PmDisp_Add ; show "add " (add frequency offset) goto PmDisp_Sub ; show "sub " (subtract frequency offset) goto PmDisp_Zero ; show "Zero" (set frequency offset to zero) goto PmDisp_StIF ; show "StdIF" (select standard IF from table) goto PmDisp_IF_1 ; show 1st standard IF from table goto PmDisp_IF_2 ; show 2nd standard IF from table goto PmDisp_IF_3 ; show 3rd standard IF from table goto PmDisp_IF_4 ; show 4th standard IF from table goto PmDisp_IF_5 ; show 5th standard IF from table goto PmDisp_Quit ; show "quit" (quit STANDARD IF menu) ; Add more display strings here if needed ! ;-------------------------------------------------------------------------- ; EXECUTION jump table for programming mode . ; Executes the commands "quit", "psave", "add", "sub", "zero", etc. ; Input parameter: menu_index (0 .. MI_INDEX_MAX) ;-------------------------------------------------------------------------- PMExecute: ; Execute the function belonging to menu_index movfw menu_index ; load menu index into W register addwf PCL, f ; add W to lower part of program counter (computed jump) goto PmExec_Quit ; quit programming mode goto PmExec_PSave; turn power-saving mode on/off goto PmExec_Add ; add frequency offset from now on goto PmExec_Sub ; subtract frequency offset from now on goto PmExec_Zero ; set frequency offset to zero goto PmExec_StIF ; switch to "Standard IF selection mode" goto PmExec_SelIF ; select 1st standard IF from table goto PmExec_SelIF ; select 2nd standard IF from table goto PmExec_SelIF ; select 3rd standard IF from table goto PmExec_SelIF ; select 4th standard IF from table goto PmExec_Quit ; quit STANDARD IF menu ; Add more jumps here if needed ! ;************************************************************************** ; * ; Procedures * ; * ;************************************************************************** ;-------------------------------------------------------------------------- ; Configure the prescaler for TIMER 0 in the PIC's OPTION register . ;-------------------------------------------------------------------------- ; Description of the OPTION register, from the PIC16F628 data sheet: ; bit 7: RBPU: PORTB Pull-up Enable bit ; 1 = PORTB pull-ups are disabled ; 0 = PORTB pull-ups are enabled by individual port latch values ; bit 6: INTEDG: Interrupt Edge Select bit ; 1 = Interrupt on rising edge of RB0/INT pin ; 0 = Interrupt on falling edge of RB0/INT pin ; bit 5: T0CS: TMR0 Clock Source Select bit ; 1 = Transition on RA4/T0CKI pin ; 0 = Internal instruction cycle clock (CLKOUT) ; bit 4: T0SE: TMR0 Source Edge Select bit ; 1 = Increment on high-to-low transition on RA4/T0CKI pin ; 0 = Increment on low-to-high transition on RA4/T0CKI pin ; bit 3: PSA: Prescaler Assignment bit ; 1 = Prescaler is assigned to the WDT ; 0 = Prescaler is assigned to the Timer0 module ; bit 2-0: PS2:PS0: Prescaler Rate Select bits, here shown for TMR0 : ; 000 = 1 : 2 ; ... 111 = 1 : 256 ; Note: to count EVERY pulse (1 : 1) with TMR0, the prescaler ; must be assigned to the WATCHDOG TIMER (WDT) ! ; Some examples (for the OPTION register, parameter in W for SetPrescaler): PSC_DIV_BY_2 equ b'00100000' ; let prescaler divide TMR0 by two PSC_DIV_BY_4 equ b'00100001' ; let prescaler divide TMR0 by 4 PSC_DIV_BY_8 equ b'00100010' ; let prescaler divide TMR0 by 8 PSC_DIV_BY_16 equ b'00100011' ; let prescaler divide TMR0 by 16 PSC_DIV_BY_32 equ b'00100100' ; let prescaler divide TMR0 by 32 PSC_DIV_BY_64 equ b'00100101' ; let prescaler divide TMR0 by 64 PSC_DIV_BY_128 equ b'00100110' ; let prescaler divide TMR0 by 128 PSC_DIV_BY_256 equ b'00100111' ; let prescaler divide TMR0 by 256 SetPrescaler: ; copy W into OPTION register, avoid watchdog trouble clrwdt ; recommended by Microchip ("switching prescaler assignment") errorlevel -302 ; Turn off banking message for the next few instructions.. bsf STATUS, RP0 ;! setting RP0 enables access to OPTION reg ; option register is in bank1. i know. thanks for the warning. movwf OPTION_REG ;! ex: "option" command (yucc) bcf STATUS, RP0 ;! clearing RP0 for normal register access errorlevel +302 ; Enable banking message again retlw 0 PrescalerOff: ; turn the prescaler for TMR0 "off" ; (actually done by assigning the prescaler to the watchdog timer) clrwdt ; clear watchdog timer clrf TMR0 ; clear timer 0 AND PRESCALER(!) errorlevel -302 ; Turn off banking message for the next few instructions.. bsf STATUS, RP0 ;! setting RP0 enables access to OPTION reg ; option register is in bank1. i know. thanks for the warning. movlw b'00100111' ;! recommended by Microchip when ;! changing prescaler assignment from TMR0 to WDT movwf OPTION_REG ;! ex: "option" command (yucc) clrwdt ;! clear watchdog again movlw b'00101111' ;! bit 3 set means PS assigned to WDT now movwf OPTION_REG ;! ex: "option" command (yucc) bcf STATUS, RP0 ;! clearing RP0 for normal register access errorlevel +302 ; Enable banking message again retlw 0 ;-------------------------------------------------------------------------- ; Power-saving subroutine: Puts the PIC to sleep for ROUGHLY 100 milliseconds . ; - crystal oscillator turned OFF during this phase ; - only the internal RC-oscillator for the watchdog keeps running ; - expiration of watchdog during sleep does NOT reset the PIC, ; only wakes it up again so normal operation may resume ; - LED display will be off during this time ;-------------------------------------------------------------------------- Sleep150ms: ; go to sleep for approx. 150 milliseconds, and then RETURN (no reset) ; Details on the PIC's watchdog timer (from PIC16F628 datasheet) : ; > The WDT has a nominal timeout period of 18 ms (with ; > no prescaler). The timeout periods vary with temperature, ; > VDD and process variations from part to part (see ; > DC specs). ; > The Watchdog Timer is a free running on-chip RC oscillator which does ; > not require any external components. This RC oscillator is separate ; > from the ER oscillator of the CLKIN pin. That means that the WDT will run, ; > even if the clock on the OSC1 and OSC2 pins of the device has been stopped, ; > for example, by execution of a SLEEP instruction. ; > During normal operation, a WDT timeout generates a device RESET. ; > If the device is in SLEEP mode, a WDT timeout causes the device to wake-up ; > and continue with normal operation. ; > The WDT can be permanently disabled by programming the configuration bit ; > WDTE as clear . ; In other words, to use the watchdog-timer for "temporary sleep" here , ; it must be ENABLED in the configuration word when programming the PIC. ; (because its not possible to turn it on via software if it's not on). ; But once the watchdog timer is ON, it must be FED periodically otherwise ; it will reset the PIC during normal operation ! ; Here (in the frequency counter), the prescaler remains assigned to timer0 ; so the watchdog interval is ~ 18 milliseconds (+/-, RC-oscillator) . ; > The CLRWDT and SLEEP instructions clear the WDT and the postscaler, ; > if assigned to the WDT, and prevent it from timing out and generating ; > a device RESET. The TO bit in the STATUS register will be cleared upon ; > a Watchdog Timer timeout. #if(COMMON_CATHODE) ; display with COMMON CATHODE : movlw 0x00 ; segment drivers LOW to turn off #else ; not COMMON CATHODE but COMMON ANODE: movlw 0xFF ; segment drivers HIGH to turn off #endif #ifndef RS232_OUT movwf LEDS_PORT ; turn LED segments off #else #ifdef NON_INVERTING_RS232_OUT bcf LEDS_PORT, 2 ; RS232 on RB2 to zero #else bsf LEDS_PORT, 2 ; RS232 on RB2 to one #endif ; NON_INVERTING_RS232_OUT #endif ; RS232_OUT ; Note: The global interrupt-enable flag (GIE) is off in this application ! ; To avoid unintended wake-up on 'interrupt' (port level change), ; disable all interrupt-SOURCES: Clear T0IE,INTE,RBIE,PEIE too : clrf INTCON ; disable all interrupts during SLEEP mode clrwdt ; clear watchdog timer clrf TMR0 ; clear timer 0 AND PRESCALER(!) errorlevel -302 ; Turn off banking message for the next few instructions.. bsf STATUS, RP0 ;! setting RP0 enables access to OPTION reg ; option register is in bank1. i know. thanks for the warning. movlw b'00101011' ;! assign PS to WDT; divide by 8 FOR WDT(!) movwf OPTION_REG ;! ex: "option" command (yucc) bcf STATUS, RP0 ;! clearing RP0 for normal register access errorlevel +302 ; Enable banking message again sleep ; sleep for approx 18 ms (one watchdog interval) ; The SLEEP command clears the Watchdog Timer and stops the main oscillator. ; Only the internal watchdog timer keeps running. ; The WDT is is also cleared when the device wakes-up from SLEEP, ; regardless of the source of wake-up, so no need for 'clrwdt' here ! nop ; arrived here, slept for ~ 8 times 18 milliseconds return ; end Sleep150ms ;-------------------------------------------------------------------------- ; Convert a character into LEDs data for the 7-segment displays, fed with ; the character in w. Bit 7 set means 'decimal point AFTER this digit' . ;-------------------------------------------------------------------------- ; WAS print 5 digits with MHz and kHz indication/. conv macro display ; macro for duplicate code movwf display ; save decimal point bit (msb) andlw 7fh ; mask bit #ifndef RS232_OUT call Digit2SevenSeg ; convert digit into 7-segment-code via table btfsc display,7 ; check bit 7 = decimal point ? #if(COMMON_CATHODE) iorlw 1<<DPPOINT_BIT ; include decimal point if bit 7 set (bitwise OR) #else ; not COMMON CATHODE but COMMON ANODE: decimal point must be 'AND'ed to pattern: andlw (1<<DPPOINT_BIT)^0xFF ; include decimal point if bit 7 set (bitwise AND) #endif movwf display ; set display data register #else ; RS232_OUT #ifdef RS232_PRINT_FIELD_3 movwf temp ; save w ; BLANK, displayed as 'C', indicates no input, going to skip printing those. bcf print_flags, NO_INPUT_FLAG ; no jumps in macro movlw BLANK subwf temp, w btfsc STATUS, Z bsf print_flags, NO_INPUT_FLAG ; get back value to print movfw temp ; test if anything other then zero, if so display it btfss print_flags, NO_INPUT_FLAG call tx_digit_in_w ; test for decimal point btfsc display, 7 call tx_dot #endif ; RS232_PRINT_FIELD_3 #endif endm ; 7 segment out conv_char0: ; display digit #0 (leftmost, or MOST SIGNIFICANT digit) conv display0 retlw 0 conv_char1: ; display #1 conv display1 retlw 0 conv_char2: ; display #2 conv display2 retlw 0 conv_char3: ; display #3 conv display3 retlw 0 conv_char4: ; display #4 (rightmost, or LEAST SIGNIFICANT digit, "ones") conv display4 #ifdef RS232_OUT #ifdef RS232_PRINT_FIELD_3 ; print a space movlw ' ' call tx_w ; test if to print kHz or MHz btfsc print_flags, KILOHERTZ_FLAG goto print_kilo ; print 'M' movlw 'M' call tx_w goto print_hertz print_kilo: movlw 'k' call tx_w ; say Hz print_hertz: movlw 'H' call tx_w movlw 'z' call tx_w #endif RS232_PRINT_FIELD_3 ; send a CR LF movlw D'10' call tx_w movlw D'13' call tx_w #endif ; RS232_OUT retlw 0 ; 7 segment out ;-------------------------------------------------------------------------- ; Fill the 5-digit display latch with blank characters ;-------------------------------------------------------------------------- ClearDisplay: movlw BLANK_PATTERN movwf display0 movwf display1 movwf display2 movwf display3 movwf display4 retlw 0 ;-------------------------------------------------------------------------- ; Save a single Byte in the PIC's Data-EEPROM. ; Input parameters: ; INDF = *FSR contains byte to be written (was once EEDATA) ; w contains EEPROM address offset (i.e. "destination index") ; ;-------------------------------------------------------------------------- ; write to EEPROM data memory as explained in the 16F628 data sheet. ; EEDATA and EEADR must have been set before calling this subroutine ; (optimized for the keyer-state-machine). ; CAUTION : What the lousy datasheet DS40300B wont tell you: ; The example given there for the 16F628 is WRONG ! ; All EEPROM regs are in BANK1 for the 16F628. ; In the PIC16F84, some were in BANK0 others in BANK1.. ; In the PIC16F628, things are much different... all EEPROM regs are in BANK1 ! SaveInEEPROM: ; save "INDF" = *FSR in EEPROM[<w>] bcf INTCON, GIE ; disable INTs errorlevel -302 ; Turn off banking message for the next few instructions.. bsf STATUS, RP0 ;!; Bank1 for "EEADR" access, PIC16F628 ONLY (not F84) movwf EEADR ;!; write into EEPROM address register (BANK1 !!) bcf STATUS, RP0 ;!; Bank0 to read "bStorageData" movfw INDF ; ; w := *FSR (read source data from BANK 0) bsf STATUS, RP0 ;!; Bank1 for "EEDATA" access, PIC16F628 ONLY (not F84) movwf EEDATA ;!; EEDATA(in BANK1) := w (BANK1; F628 only, NOT F84 !!!) bsf EECON1, WREN ;!; set WRite ENable bcf INTCON, GIE ;!; Is this REALLY required as in DS40300B Example 13-2 ? movlw 055h ;!; movwf EECON2 ;!; write 55h movlw 0AAh ;!; movwf EECON2 ;!; write AAh bsf EECON1, WR ;!; set WR bit, begin write ; wait until write access to the EEPROM is complete. SaveEW: btfsc EECON1, WR ;!; WR is cleared after completion of write goto SaveEW ;!; WR=1, write access not finished yet ; Arrived here: the EEPROM write is ready bcf EECON1, WREN ;!; disable further WRites bcf STATUS, RP0 ;!; Bank0 for normal access errorlevel +302 ; Enable banking message again ; bsf INTCON, GIE ; enable INTs ? NOT IN THIS APPLICATION ! retlw 0 ; end SaveInEEPROM ;-------------------------------------------------------------------------- ; Read a single Byte from the PIC's Data-EEPROM. ; Input parameters: ; w contains EEPROM address offset (i.e. "source index") ; will *NOT* be modified to simplify block-read . ; FSR points to the memory location where the byte shall be placed. ; ; Result: ; INDF = *FSR returns the read byte ;-------------------------------------------------------------------------- ; Caution: EEDATA and EEADR have been moved from Bank0(16F84) to Bank1(16F628) ; and the example from the datasheet telling you to switch to ; bank0 to access EEDATA is rubbish (DS40300B page 93 example 13-1). EEPROM_ReadByte: ; read ONE byte from the PIC's data EEPROM movwf bTemp ; save W bcf INTCON, GIE ; disable INTs errorlevel -302 ; Turn off banking message for the next few instructions.. bsf STATUS, RP0 ; Bank1 for ***ALL*** EEPROM registers in 16F628 (!) movwf EEADR ;! write into EEPROM address register bsf EECON1, RD ;! set "Read"-Flag for EEPROM ; why is EECON1.RD not cleared in MPLAB-sim ?!? movf EEDATA, w ;! read byte from EEPROM latch bcf STATUS, RP0 ;! normal access to Bank0 errorlevel +302 ; Enable banking message again ; bsf INTCON, GIE ; re-enable interrupts ? NOT IN THIS APPLICATION ! movwf INDF ; place result in *FSR movfw bTemp ; restore W return ; back to caller ; end EEPROM_ReadByte EEPROM_Read4Byte: ; read FOUR bytes from the PIC's data EEPROM. ; Input parameters: ; w contains EEPROM address offset (i.e. "source index") ; will *NOT* be modified to simplify block-read . ; FSR points to the memory location where the byte shall be placed. call EEPROM_ReadByte ; *FSR = EEPROM[w] (usually bits 31..24) addlw 1 ; next source address incf FSR , f ; next destination address call EEPROM_ReadByte ; *FSR = EEPROM[w] (usually bits 23..16) addlw 1 ; next source address incf FSR , f ; next destination address call EEPROM_ReadByte ; *FSR = EEPROM[w] (usually bits 15..8) addlw 1 ; next source address incf FSR , f ; next destination address goto EEPROM_ReadByte ; *FSR = EEPROM[w] (usually bits 7..0) ; end EEPROM_Read4Byte ;-------------------------------------------------------------------------- ; Count pulses, fed with the number of loop iterations for the gate time . ; WHILE counting, the multiplexed LED display is updated . ; Watchdog is fed in this loop ! ; Input: Count of gate-time-loops in 'gatecnt_hi'+'gatecnt_lo' (16 bit). ; Returns: The number of pulses in 'freq' (clock cycles in []) ;-------------------------------------------------------------------------- count_pulses: clrf freq_hi ; clear pulse counter (bits 31..24) clrf freq_mh ; bits 23..16 clrf freq_ml ; bits 16..8 clrf freq_lo ; bits 7..0 clrf timer0_old ; 'old' value of timer0 to detect toggling MSB clrf TMR0 ; timer register (PIC's hardware timer, 8 bit) nop ; 2 instruction cycle delay nop ; after writing to TMR0 (MPLAB-SIM: set breakpoint + clear stopwatch here) ; --------------- start of critial timing loop >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ; The following timing loop must take a well-defined time in total per ; iteration, usually 50 (or 20) microseconds, which can be precisely achieved ; with a 4-MHz-crystal (or 20 MHz for variant 2+3) . ; This gives a basic delay for the frequency counter's gate time . ; The frequency at the input of TIMER 0 (not the prescaler) ; can not exceed f_crystal / 4, ; and every HIGH->LOW transition of bit7 in TIMER0 must be polled here. ; This is safe because .. ; Variant 1: With a 4-MHz-crystal, Timer0 can count up to 1 MHz input, ; MSB toggles every (128/1MHz) = 128 us, polled every 50us -> ok. ; Variant 2: With a 20-MHz-crystal, Timer0 can count up to 4 (not 5?!) MHz input, ; MSB toggles every (128/4MHz) = 32 us, polled every 20us -> ok. ; The numbers in square brackets below are the INSTRUCTION NUMBER within the loop. ; (not the count of oscillator cycles for a single command, which is always 4). ; These values can be checked with the "Stopwatch" function in MPLAB-SIM. ; The goal is to let this loop take EXACTLY <TIME> microseconds (50us or 20us). count1 movfw disp_index ; [1] get the current digit number (disp_index = 0..4) call Digit2MuxValue ; [2,3,4,5,6,7] display (6 commands including call+retlw) movwf bTemp ; [8] save the bit pattern for the multiplexer port movlw display0 ; [9] get the LED display data for the current digit... addwf disp_index,w ; [10] add current digit number to address of LED data movwf FSR ; [11] move address into the PIC's poor 'data pointer' #ifndef RS232_OUT movfw INDF ; [12] w := *(FSR) use indirection register to read from table movwf LEDS_PORT ; [13] set the LED segments #else ; leave port B alone, so as not to disturb RS232 software out. nop nop #endif movfw bTemp ; [14] get the mupliplexer pattern (hurry, hurry !) movwf ENABLE_PORT ; [15] set the LED multiplexer incf disp_timer,f ; [16] increment display-multiplex timer btfsc disp_timer,6 ; [17] (6-bit prescaler) incf disp_index,f ; [18] next display if rolled over bcf disp_timer,6 ; [19] limit disp_timer to 6 bits (!) movfw disp_index ; [20] limit display index to 0...4 sublw .4 ; [21] subtract #4 - W register -> C=0(!) if result negative (W>4) btfss STATUS,C ; [22] skip next instruction if C=1 (#4-W >= 0) clrf disp_index ; [23] if C=0 (disp_index>4) then disp_index=0 ; the following fragments of code always take the same number of clock ; cycles to execute, irrespective of whether the skips take place or not . ; Here still in 'count_pulses'. movfw TMR0 ; [24] read least significant byte of movwf freq_lo ; [25] pulse counter (bits 7..0) movlw 1 ; [26] determine if timer 0 has rolled btfss timer0_old,7 ; [27] over (rolled over if msb was clrw ; [28] previously set and now isn't) btfsc freq_lo,7 ; [29] clrw ; [30] addwf freq_ml,f ; [31] increment high bytes of pulse counter skpnc ; [32] if low byte rolled over incf freq_mh,f ; [33] (mh = "medium high byte" of counter) ; NOTE: we are not modifying freq_hi here ! ; Bits 31..24 may be used later when multiplying with some factor ; (2^n) to compensate for the ASYNCHRON PRESCALER ! btfsc freq_mh,7 ; [34] overflow (freq > 7fffffh) ? goto count3 ; [35] branch if yes movfw freq_lo ; [36] save previous value from timer 0 movwf timer0_old ; [37] tstf gatecnt_lo ; [38] check inner gate-time counter, LOW byte skpnz ; [39] only decrement h-byte if l-byte zero decf gatecnt_hi,f ; [40] decrement gate-time counter, HIGH byte decf gatecnt_lo,f ; [41] always decrement gate-time counter, LOW byte #if (DISP_VARIANT==1) ; only 50 instruction cycles per loop in DISPLAY VARIANT 1 (f_xtal=4 MHz, t_loop=50us) ; Got some instruction cycles left ? Insert a few NOPs to bring to total loop time to 50us. clrwdt ; [42] (ex: nop, but since 2006-05-28 the dog must be fed !) nop ; [43] nop ; [44] nop ; [45] ugh, what a waste of precious CPU power ;-) movfw gatecnt_hi ; [46] counter = 0 ? iorwf gatecnt_lo,w ; [47] skpz ; [48] goto count1 ; [49,50] goto always takes TWO instruction cycles #else ; For VARIANTS 2+3 : 100 instruction cycles per loop ; (f_xtal=20 MHz, t_loop=20us, t_instr=4/20MHz=0.2us) ; Some time may be used for a nice software-based PULSE WIDTH MODULATION ; of the display intensity ... or other goodies/gimmicks one fine day ! clrwdt ; [42] (ex: nop, but since 2006-05-28 the dog must be fed !) movlw .12 ; [43] load additional delay loops (X=12, see below) into W WasteT1: addlw 0xFF ; [44, 48, .. ] btfss STATUS, Z ; [45, 49, .. ] eats 4(!) INSTRUCTION CYCLES per loop goto WasteT1 ; [46+47,50+51, .. ] ; Check this with MPLAB-SIM: here, after loop: [43 + 4*X], with X=12: [91] nop ; [91] nop ; [92] nop ; [93] nop ; [94] nop ; [95] movfw gatecnt_hi ; [96] counter = 0 ? iorwf gatecnt_lo,w ; [97] skpz ; [98] goto count1 ; [99,50] goto always takes TWO instruction cycles #endif ; variant 1 or variant 2/3 ? ; <<<<<<<<<<<<<<<<<<<<<<<< end of timing loop ----------------------------- movfw TMR0 ; get final value from timer 0 movwf freq_lo movlw 1 ; determine if timer 0 has rolled btfss timer0_old,7 ; over (rolled over if msb was clrw ; previously set and now isn't) btfsc freq_lo,7 clrw addwf freq_ml,f ; increment high bytes of pulse skpnc ; counter if low byte rolled incf freq_mh,f ; over count3 retlw 0 ; end of routine 'count_pulses'. Result now in freq_lo..freq_hi. #ifdef RS232_OUT tx_dot: movlw '.' call tx_w return ; send_one_char ; the actual RS232 transmission routine, half-duplex, no-flow-control. ; See AN510 for an explanation tx_digit_in_w: addlw '0' ; zero tx_w: banksel 0 ; return ; movlw 'A' movwf tx_reg ; move W (char to send) to TXReg movlw 0x08 movwf bit_count ; send 8 bits ; send start bit #ifdef NON_INVERTING_RS232_OUT bsf RS232_PORT, RS232_BIT #else bcf RS232_PORT, RS232_BIT #endif nop nop nop nop call bit_delay ; send data bits send_next_bit: bcf STATUS, C rrf tx_reg, 1 ; rotate TXReg btfsc STATUS, C goto set_tx clear_tx: nop ; to get equal set/clear times #ifdef NON_INVERTING_RS232_OUT bsf RS232_PORT, RS232_BIT #else bcf RS232_PORT, RS232_BIT #endif goto ready_tx set_tx: #ifdef NON_INVERTING_RS232_OUT bcf RS232_PORT, RS232_BIT #else bsf RS232_PORT, RS232_BIT #endif goto ready_tx ready_tx: call bit_delay decfsz bit_count,1 ; decrement bit counter (8..0) goto send_next_bit ; loop for next data bit nop nop nop nop nop ; send first stop bit #ifdef NON_INVERTING_RS232_OUT bcf RS232_PORT, RS232_BIT #else bsf RS232_PORT, RS232_BIT #endif call bit_delay ; send second stop bit ; call bit_delay return ; This routine is calibrated with BIT_DELAY to 104 us, that makes BAUD_DIVIDER 1 for 9600 Bd, 2 for 4800 Bd, 4 for 2400 Bd, 8 for 1200 Bd, 16 for 600 Bd, 32 for 300 Bd, 64 for 150 Bd, and 128 for 75 Bd. bit_delay: ; prevent watchdog from interrupting serial com clrwdt ; should be called on a regular basis ; Multiply bit delay for lower baudrates. movlw BAUD_DIVIDER movwf baud_divider baud_divider_loop: ; this is the delay of about 104 uS for 9600 Bd movlw BIT_DELAY ; move baud delay constant to W movwf delay_counter ; initialize delay counter us100_delay_loop: decfsz delay_counter ; decrement delay counter goto us100_delay_loop decfsz baud_divider goto baud_divider_loop return #endif ; RS232_OUT ;-------------------------------------------------------------------------- ; Convert *FSR (32 bit) into BCD and show it on the display . ; Input : INDF = *FSR, 32-bit integer. ; Bad side effect : CONTENTS OF <freq> will be lost !! ;-------------------------------------------------------------------------- ShowInt32_FSR ; Convert <*FSR> (32 bit integer) to 8 BCD-digits ... movfw INDF ; W := *FSR , load LOW byte incf FSR , f ; FSR := FSR + 1 movwf freq ; freq.hi := W movfw INDF ; W := *FSR , load MIDDLE LOW byte incf FSR , f ; FSR := FSR + 1 movwf freq+1 ; freq.mh := W movfw INDF ; W := *FSR , load MIDDLE HIGH byte incf FSR , f ; FSR := FSR + 1 movwf freq+2 ; freq.ml := W movfw INDF ; W := *FSR , load HIGH byte incf FSR , f ; FSR := FSR + 1 movwf freq+3 ; freq.lo := W ; continue with CvtAndDisplayFreq ! ;-------------------------------------------------------------------------- ; Convert <freq> into BCD and show it on the display . ; Input : freq, 32-bit integer. CONTENTS OF <freq> will be lost !! ;-------------------------------------------------------------------------- CvtAndDisplayFreq ; Convert <freq>(32 bit integer) to 8 BCD-digits ... clrf tens_index ; initialise the table index movlw digits ; initialise the indirection register movwf FSR ; ( FSR="pointer"; *FSR=INDF) conv1 ; Loop for ALL POWERS OF TEN in the lookup table.. clrwdt ; feed the watchdog (may stay a bit longer) movfw tens_index ; fetch the next power of ten call TensTable ; (32 bits) from the lookup table movwf divi+0 ; and store in divi incf tens_index , f ; this was the HIGH byte movfw tens_index call TensTable movwf divi+1 incf tens_index , f ; this was the MIDDLE-HIGH byte movfw tens_index call TensTable movwf divi+2 incf tens_index , f ; this was the MIDDLE-LOW byte movfw tens_index call TensTable movwf divi+3 incf tens_index , f ; and this was the LOW-byte of a power of ten ; ex: clrf 0 ; clear the decimal digit .. but address ZERO is called 'INDF' these days ! clrf INDF ; *FSR = 0 conv2 ; Loop to repeatedly subtract divi from freq (32-bit subtract) ; until underflow while incrementing the decimal digit. sub32 freq,divi ; freq := freq - divi (with divi = 10 power N) bnc conv3 ; incf INDF , f ; The RESULT will be written back to freq, goto conv2 ; in other words 'freq' will be lost ! conv3 add32 freq,divi ; freq := freq+divi; ready for next digit incf FSR , f ; step to next decimal digit movlw 8*4 ; 8 x 4-byte entries in TensTable subwf tens_index,w bnz conv1 ; loop until end of table ;-------------------------------------------------------------------------- ; displays the frequency in decimal ;-------------------------------------------------------------------------- display_freq: ; Display the decimal digits according to the following rules ; 000000A => "0.00A" ; 00000AB => "0.0AB" ; 0000ABC => "0.ABC" ; 000ABCD => "A.BCD" ; 00ABCDE => "AB.CD" ; 0ABCDEF => "ABC.D" ; ABCDEFG => "ABCD." ; Modified a lot by WoBu to display kHz as well as MHz : ; If the decimal point means kHz, it flashes. ; If it means MHz, it is on permanently. ; 24 bit unsigned integer could count up to 16777216 (16 mio, slightly over 7 digits) ; which was not enough for a 50 MHz counter, so switched to 32-bit arithmetic . ; #ifdef RS232_OUT #ifdef RS232_PRINT_FIELD_1 ; WAS print 8 digits as one field for parsin gby user programs, no leading zero suppression ; print_value simple movlw digits movwf FSR movfw INDF call tx_digit_in_w incf FSR movfw INDF call tx_digit_in_w incf FSR movfw INDF call tx_digit_in_w incf FSR movfw INDF call tx_digit_in_w incf FSR movfw INDF call tx_digit_in_w incf FSR movfw INDF call tx_digit_in_w incf FSR movfw INDF call tx_digit_in_w incf FSR movfw INDF call tx_digit_in_w ; print 2 spaces movlw ' ' call tx_w movlw ' ' call tx_w #endif ; RS232_PRINT_FIELD_1 #ifdef RS232_PRINT_FIELD_2 ; print value in Hz, with leading zero surpression ; print_value: thoudands separated by commas bsf print_flags, ZERO_SUPPRESSION_FLAG movlw digits movwf FSR tstf INDF bz pri_1000000 pri_10000000: bcf print_flags, ZERO_SUPPRESSION_FLAG movfw INDF tstf INDF bz pri_100000 call tx_digit_in_w pri_1000000: incf FSR ; test if zero supression active btfss print_flags, ZERO_SUPPRESSION_FLAG goto pri_a tstf INDF bz pri_100000 pri_a: bcf print_flags, ZERO_SUPPRESSION_FLAG movfw INDF call tx_digit_in_w movlw ',' call tx_w pri_100000: incf FSR btfss print_flags, ZERO_SUPPRESSION_FLAG goto pri_b tstf INDF bz pri_10000 pri_b: bcf print_flags, ZERO_SUPPRESSION_FLAG movfw INDF call tx_digit_in_w pri_10000: incf FSR btfss print_flags, ZERO_SUPPRESSION_FLAG goto pri_c tstf INDF bz pri_1000 pri_c: bcf print_flags, ZERO_SUPPRESSION_FLAG movfw INDF call tx_digit_in_w pri_1000: incf FSR btfss print_flags, ZERO_SUPPRESSION_FLAG goto pri_d tstf INDF bz pri_100 pri_d: bcf print_flags, ZERO_SUPPRESSION_FLAG movfw INDF call tx_digit_in_w movlw ',' call tx_w pri_100: incf FSR btfss print_flags, ZERO_SUPPRESSION_FLAG goto pri_e tstf INDF bz pri_10 pri_e: bcf print_flags, ZERO_SUPPRESSION_FLAG movfw INDF call tx_digit_in_w pri_10: incf FSR btfss print_flags, ZERO_SUPPRESSION_FLAG goto pri_f tstf INDF bz pri_1 pri_f: bcf print_flags, ZERO_SUPPRESSION_FLAG movfw INDF call tx_digit_in_w pri_1: incf FSR movfw INDF call tx_digit_in_w pri_space: ; space movlw ' ' call tx_w ; Hz movlw 'H' call tx_w movlw 'z' call tx_w ; print 2 spaces movlw ' ' call tx_w movlw ' ' call tx_w #endif ; RS232_PRINT_FIELD_2 #endif ; RS232_OUT ; Display routine for frequencies up to "99.99 MHz" (theoretical): ; (do NOT insert the decimal point yet, ; it would disturb the blanking of LEADING zeroes ) movlw digits ; find the first significant digit.. movwf FSR ; .. by stepping over leading zeroes tstf INDF ; INDF = *(FSR) in "C" syntax, FSR points to 'digits' bnz displ_MHz ; 10-MHz-digit non-zero, show frequency in MHz incf FSR , f ; otherwise skip 1st digit (the 10-MHz place) tstf INDF bnz displ_MHz ; 1-MHz-digit non-zero, show frequency in MHz incf FSR , f ; otherwise skip 2nd digit (the 1-MHz place) tstf INDF bnz displ_kHz ; 100-kHz-digit non-zero, show frequency in kHz (XXX.X) incf FSR , f ; otherwise skip 3rd digit (the 100-kHz place) tstf INDF bnz displ_kHz ; 10-kHz-digit non-zero, show frequency in kHz (XX.XX) incf FSR , f ; Otherwise show digits 5,6,7,8 (there are EIGHT digits) ; show all these frequencies with flashing kHz-point (X.XXX) displ_kHz: ; insert a BLINKING POINT to indicate the kilohertz-digit #ifndef RS232_OUT btfsc blinker, 0 ; check the blink flag (bit 0) for the kHz-point #endif ; RS232_OUT ; in RS232_OUT we always have a dot if kHz (non blinking). bsf digit_4, 7 ; set the decimal point indicating the frequency in kHz . bsf print_flags, KILOHERTZ_FLAG goto display displ_MHz: ; insert a BLINKING POINT to indicate the kilohertz-digit bsf digit_1, 7 ; set the decimal point indicating the frequency in MHz . bcf print_flags, KILOHERTZ_FLAG display: ; Show the FIVE digits beginning at INDF = *(FSR) on the LED display... movfw INDF ; convert the four digits to call conv_char0 ; LED display data incf FSR , f ; increment pointer to next digit movfw INDF ; w = *(FSR) call conv_char1 ; second visible digit incf FSR , f movfw INDF call conv_char2 ; third visible digit incf FSR , f movfw INDF call conv_char3 ; fourth visible digit incf FSR , f movfw INDF goto conv_char4 ; convert fifth visible digit AND RETURN ; end of routine "CvtAndDisplayFreq" ;-------------------------------------------------------------------------- ; main entry point ;-------------------------------------------------------------------------- MainInit: #IF 0 ; Test some math macros ? clrf freq2_hi clrf freq2_mh clrf freq2_ml movlw .100 movwf freq2_lo neg32 freq2 ; -100 = 0xFFFFFF9C #ENDIF ; Test ! movlw PORT_A_IO ; initialise port A errorlevel -302 ; Turn off banking message for the next few instructions.. bsf STATUS, RP0 ;! setting RP0 enables access to TRIS regs movwf PORTA ;! looks like PORTA but is in fact TRISA bcf STATUS, RP0 ;! clearing RP0 enables access to PORTs clrf PORTA movlw PORT_B_IO ; initialise port B bsf STATUS, RP0 ;! setting RP0 enables access to TRIS regs movwf PORTB ;! looks like PORTB but is in fact TRISB bcf STATUS, RP0 ;! clearing RP0 enables access to PORTs errorlevel +302 ; Enable banking message again clrf PORTB clrf disp_index ; initialise display index and clrf disp_timer ; display multiplex timer movlw BLANK ; blank character as dummy ... movwf digit_8 ; for the lowest frequency display range movlw TEST ; test all LED segments call conv_char0 movlw TEST call conv_char1 movlw TEST call conv_char2 movlw TEST call conv_char3 movlw TEST call conv_char4 movlw PSC_DIV_BY_256 ; let the prescaler divide by 256 while testing.. call SetPrescaler ; safely write <W> into option register #if(DEBUG==0) ; Do a LAMP TEST for half a second, including all decimal points : movlw (LAMPTEST_LOOPS)>>8 ; high byte for 0.5 second lamp test movwf gatecnt_hi movlw (LAMPTEST_LOOPS)&0ffh ; low byte for 0.5 second lamp test movwf gatecnt_lo call count_pulses ; some delay to show the test pattern #endif ; not DEBUG MainRestart: ; Here we "restart" the counter after exiting from programming mode : clrf psave_timer ; clear timer for power-save mode (no immediate power-down) clrf psave_flags ; clear all power-saving flags (PSFLAG_ACTIVE, etc) movlw foffs ; load destination address for reading from EEPROM... movwf FSR ; ..into the PIC's pointer register movlw EEPROM_ADR_FREQ_OFFSET+0 ; load the EEPROM-internal address offset (=source index) call EEPROM_Read4Byte ; read from EEPROM: foffs..foffs+4 := EEPROM[W] movlw options ; another destination address for reading from EEPROM.. movwf FSR ; movlw EEPROM_ADR_OPTIONS ; load EEPROM-internal offset of "options"-byte call EEPROM_ReadByte ; read single byte from EEPROM: options := EEEPROM[W] #if(DEBUG==1) bsf OPT_PWRSAVE ; enable power-save mode for debugger/simulator #endif ; DEBUG ; Blank the display until 1st measurement is available : call ClearDisplay ;-------------------------------------------------------------------------- ; main loop : Preparation, auto ranging, measurement, conversion, display ;-------------------------------------------------------------------------- MainLoop: ; re-initialise ports ; ex: tris PORTA; tris PORTB errorlevel -302 ; Turn off banking message for the next few instructions.. bsf STATUS, RP0 ;! setting RP0 enables access to TRIS regs movlw PORT_A_IO ;! movwf PORTA ;! looks like PORTA but is in fact TRISA movlw PORT_B_IO ;! movwf PORTB ;! looks like PORTB but is in fact TRISB bcf STATUS, RP0 ;! clearing RP0 enables access to PORTs clrwdt ; configure TMR0... but clear watchdog timer first movlw b'100000' ; value for OPTION reg: edge - low-to-high transition, ; + prescaler assigned to Timer 0, 1:2 bsf STATUS, RP0 ;! setting RP0 enables access to OPTION reg ; option register is in bank1. i know. thanks for the warning. movwf OPTION_REG ;! ex: "option" command (yucc) bcf STATUS, RP0 ;! clearing RP0 for normal register access errorlevel +302 ; Enable banking message again #ifdef BAUDRATE_TEST test1: movlw 'A' call tx_w call bit_delay call bit_delay call bit_delay call bit_delay call bit_delay call bit_delay call bit_delay call bit_delay call bit_delay call bit_delay call bit_delay call bit_delay call bit_delay call bit_delay call bit_delay call bit_delay call bit_delay call bit_delay goto test1 #endif ; BAUDRATE_TEST ; First do a 'range-detection measurement' to find ; a suitable prescaler ratio. Worst-case-estimation: ; 50 MHz at the input of the async TIMER 0 prescaler ; requires a prescaler ratio of 64 because ; the synchron counter in TIMER 0 accepts a maximum ; frequency of f_osc / 4, here: max. 1 MHz. ; The theoretic maximum frequency is 64 MHz then, which ; was almost reached when tested with a PIC 16F628 . ; The range-detection interval is somewhere near 1/30 seconds (see RANGE_DET_LOOPS), ; so frequencies below 30*64 = 1920 Hz are not detectable at this step. RANGE_DET_LOOPS equ CLOCK/(.30*CYCLES) ; number of gate-time loops to detect the MEASURING RANGE ; (which is required to find a good prescaler value) movlw (RANGE_DET_LOOPS)>>8 ; high byte for RANGE DETECTION loop counter movwf gatecnt_hi movlw (RANGE_DET_LOOPS)&0ffh ; low byte for RANGE DETECTION loop counter movwf gatecnt_lo movlw PSC_DIV_BY_64 ; let the prescaler divide by 64 while testing.. call SetPrescaler ; safely write <W> into option register call count_pulses ; count pulses for the range detection interval (1/16 sec) ; The result will be placed in freq_lo,freq_ml,freq_mh,freq_hi (32 bit) ; but the max count at 64 MHz input, 1/30 sec gate time, and prescaler=64 will be : ; 64MHz / (30 * 64) = 33333 pulses, so only 16 bits in the counter ; are required here (call them "testcount", f_in = testcount * 30*64) . ; The frequency resolution of this coarse measurement is 64*16 Hz = roughly 1 kHz. ; (for that reason it's not suited for "wake-up from power-save on frequency-change") #if 0 ; TEST auto ranging movlw (.8500)>>8 ; high byte of counted pulses movwf freq_ml movlw (.8500)&0ffh ; low byte of counted pulses movwf freq_lo #endif ; end TEST ; Load the default (soft-)counters for the GATE TIME. ; Most measuring ranges use a 1/4 second gate time ! movlw (GATE_TIME_LOOPS/4)>>8 ; high byte of gate time movwf gatecnt_hi movlw (GATE_TIME_LOOPS/4)&0ffh ; low byte of gate time movwf gatecnt_lo ; Increment the "blinker" once every 0.25 seconds. ; (if the gate time is longer, flashing will be slower, that's acceptable) incf blinker, f incf psave_timer, f ; increment the power-save timer every 0.25 seconds too (checked somewhere else) ; Look at the range-detection count ("testcount") ; and decide which measuring range to use, beginning with the highest frequency range #if (DISP_VARIANT==1) ; Ranges FOR VARIANT 1, 4 MHz CRYSTAL (low-power variant, less resolution at HF !) ; Rng testcount f_in prescaler gate_time display, resolution ; (1) 0..6 0.. 11.5 kHz 1 1 second X.XXXkHz, 0.001kHz (4 digits only) ; (2) 7..54 ..103.6 kHz 1 1/2 second XX.XXXkHz, 0.002kHz (last digit steps by 2) ; (3) 55..511 ..981.1 kHz 1 1/4 second XXX.XXkHz, 0.004kHz (last digit steps by 1) ; (4) 512..1023 .. 1.9 MHz 2 1/4 second XXX.XXkHz, 0.008kHz (last digit steps by 1) ; (5) 1024..2047 .. 3.9 MHz 4 1/4 second X.XXXXMHz, 0.016kHz (last digit steps by 1) ; (6) 2048..4095 .. 7.9 MHz 8 1/4 second X.XXXXMHz, 0.032kHz (last digit steps by 1) ; (7) 4096..8191 ... 15.7 MHz 16 1/4 second X.XXXXMHz, 0.064kHz (last digit steps by 1) ; (8) 8192..16383 ... 31.4 MHz 32 1/4 second X.XXXXMHz, 0.128kHz (last digit steps by 1 or 2) ; (9) 16384..33300 ... 63.9 MHz 64 1/4 second XX.XXXMHz, 0.256kHz (last digit steps by 1) movfw freq_ml ; first look at bits 15..8 of the 'test count' result andlw b'11000000' ; any of bits 15..14 set (>=16384) -> no Z flag -> range 9 btfss STATUS,Z ; skip next instruction if ZERO-flag set (!) goto Range9 ; far jump to range 9 btfsc freq_ml,5 ; bit 13 set (>=8192) -> range 8 goto Range8 btfsc freq_ml,4 ; bit 12 set (>=4096) -> range 7 goto Range7 btfsc freq_ml,3 ; bit 11 set (>=2048) -> range 6 goto Range6 btfsc freq_ml,2 ; bit 10 set (>=1024) -> range 5 goto Range5 btfsc freq_ml,1 ; bit 9 set (>=512) -> range 4 goto Range4 btfsc freq_ml,0 ; bit 8 set (>=256) -> no Z flag -> range 3 goto Range3 movfw freq_lo ; now look at bits 7..0 only .. sublw .54 ; subtract #54 - W register -> C=0 if result negative btfss STATUS,C ; skip next instruction if C=1 (#54-W >= 0) goto Range3 ; freq > 100kHz -> also range 3 movfw freq_lo ; look at bits 7..0 again .. sublw .5 ; subtract #5 - W register -> C=0 if result negative btfss STATUS,C ; skip next instruction if C=1 goto Range2 ; freq > 10kHz -> range 2 goto Range1 ; otherwise range 1 #endif ; end of specific range-switching for DISPLAY VARIANT #1 #if (DISP_VARIANT==2) || (DISP_VARIANT==3) ; Ranges FOR VARIANT 2+3, 20 MHz CRYSTAL (draws more power, but gives better resolution at HF ) ; Even if PIC clocked with 20MHz, keep the input of TIMER0 below 4(!) MHz . ; Rng testcount f_in prescaler gate_time display, resolution ; (1) 0..6 0.. 11.5 kHz 1 1 second X.XXXkHz, 0.001kHz (4 digits only) ; (2) 7..54 ..103.6 kHz 1 1/2 second XX.XXXkHz, 0.002kHz (last digit steps by 2) ; (3) 44..2047 .. 3.9 MHz 1 1/4 second X.XXXXMHz, 4 Hz (last digit steps by 1) ; (4) 2048..4095 .. 7.9 MHz 2 1/4 second X.XXXXMHz, 8 Hz (last digit steps by 1) ; (5) 4096..8191 ... 15.7 MHz 4 1/4 second X.XXXXMHz, 16 Hz (last digit steps by 1) ; (6) 8192..16383 ... 31.4 MHz 8 1/4 second X.XXXXMHz, 32 Hz (last digit steps by 1 or 2) ; (7) 16384..33330 ... 63.9 MHz 16 1/4 second XX.XXXMHz, 64 Hz (last digit steps by 1) movfw freq_ml ; first look at bits 15..8 of the 'test count' result andlw b'11000000' ; any of bits 15..14 set (>=16384) -> no Z flag -> range 7 btfss STATUS,Z ; skip next instruction if ZERO-flag set (!) goto Range7 ; far jump to range 7 btfsc freq_ml,5 ; bit 13 set (>=8192) -> range 6 goto Range6 btfsc freq_ml,4 ; bit 12 set (>=4096) -> range 5 goto Range5 btfsc freq_ml,3 ; bit 11 set (>=2048) -> range 4 goto Range4 btfsc freq_ml,2 ; bit 10 set (>=1024) -> range 3 goto Range3 btfsc freq_ml,1 ; bit 9 set (>=512) -> range 3 goto Range3 btfsc freq_ml,0 ; bit 8 set (>=256) -> no Z flag -> range 3 goto Range3 movfw freq_lo ; now look at bits 7..0 only .. sublw .54 ; subtract #54 - W register -> C=0 if result negative btfss STATUS,C ; skip next instruction if C=1 (#54-W >= 0) goto Range3 ; freq > 100kHz -> also range 3 movfw freq_lo ; look at bits 7..0 again .. sublw .5 ; subtract #5 - W register -> C=0 if result negative btfss STATUS,C ; skip next instruction if C=1 goto Range2 ; freq > 10kHz -> range 2 goto Range1 ; otherwise range 1 (lowest frequencies) #endif ; end of specific range-switching for DISPLAY VARIANT #2 Range1: ; Range 1: async prescaler off, 1 second gate time for very low frequencies : call PrescalerOff ; turn hardware prescaler off incf psave_timer, f ; increment power-save timer three more times incf psave_timer, f ; (1 sec-gate instead of 0.25) incf psave_timer, f ; Load the GATE TIMER (as count of loops) for this measuring range. movlw (GATE_TIME_LOOPS)>>8 ; high byte for 1 second gate time movwf gatecnt_hi movlw (GATE_TIME_LOOPS)&0ffh ; low byte for 1 second gate time movwf gatecnt_lo ; Load the count of "left shifts" to compensate gate time + prescaler : movlw 0 ; no need to multiply with prescaler 1:1 and 1-sec gate time goto GoMeasure Range2: ; Range 2: async prescaler off, 1/2 second gate time for quite low frequencies : call PrescalerOff ; turn hardware prescaler off incf psave_timer, f ; increment power-save timer one more time (0.5 sec-gate instead of 0.25) ; Load the GATE TIMER (as count of loops) for this measuring range. movlw (GATE_TIME_LOOPS/2)>>8 ; high byte for 1/2 second gate time movwf gatecnt_hi movlw (GATE_TIME_LOOPS/2)&0ffh ; low byte for 1/2 second gate time movwf gatecnt_lo ; Load the count of "left shifts" to compensate gate time + prescaler : movlw 1 ; multiply by 2 (=2^1) later to compensate gate time (1/2 s) goto GoMeasure Range3: ; Range 3: async prescaler off, gate time = default (1/4 sec) : call PrescalerOff ; turn hardware prescaler off movlw 2 ; multiply by 4 (=2^2) later to compensate gate time (1/4 s) goto GoMeasure Range4: ; Range 4: prescaler divide by 2 , gate time = default (1/4 sec) : movlw PSC_DIV_BY_2 ; let the prescaler divide by 2 while MEASURING... call SetPrescaler ; safely write <W> into option register movlw 3 ; multiply by 8 (=2^3) later to compensate prescaling (1:2) * gate time (1/4 s) goto GoMeasure Range5: ; Range 5: prescaler divide by 4 , gate time = default (1/4 sec) : movlw PSC_DIV_BY_4 ; let the prescaler divide by 2 while MEASURING... call SetPrescaler ; safely write <W> into option register movlw 4 ; multiply by 16 (=2^4) later to compensate prescaling (1:4) * gate time (1/4 s) goto GoMeasure Range6: ; Range 6: prescaler divide by 8 , gate time = default (1/4 sec) : movlw PSC_DIV_BY_8 ; let the prescaler divide by 2 while MEASURING... call SetPrescaler ; safely write <W> into option register movlw 5 ; multiply by 32 (=2^5) later to compensate prescaling (1:8) * gate time (1/4 s) goto GoMeasure Range7: ; Range 7: prescaler divide by 16 , gate time = default (1/4 sec) : movlw PSC_DIV_BY_16 ; let the prescaler divide by 2 while MEASURING... call SetPrescaler ; safely write <W> into option register movlw 6 ; multiply by 64 (=2^6) later to compensate prescaling (1:16) * gate time (1/4 s) goto GoMeasure #if (DISP_VARIANT==1) ; Ranges 8 + 9 are only needed for VARIANT 1 with 4-MHz crystal : Range8: ; Range 8: prescaler divide by 32 , gate time = default (1/4 sec) : movlw PSC_DIV_BY_32 ; let the prescaler divide by 2 while MEASURING... call SetPrescaler ; safely write <W> into option register movlw 7 ; multiply by 128 (=2^7) later to compensate prescaling (1:32) * gate time (1/4 s) goto GoMeasure Range9: ; Range 9: prescaler divide by 64 , gate time = default (1/4 sec) : movlw PSC_DIV_BY_64 ; let the prescaler divide by 2 while MEASURING... call SetPrescaler ; safely write <W> into option register movlw 8 ; multiply by 256 (=2^8) later to compensate prescaling (1:64) * gate time (1/4 s) goto GoMeasure #endif ; (DISP_VARIANT==1) GoMeasure: movwf adjust_shifts ; save the number of "arithmetic left shifts" for later call count_pulses ; count pulses for 1, 1/2, or 1/8 s . ; Result in freq_lo,freq_ml,freq_mh,freq_hi (32 bit) now, ; NOT adjusted for the gate-time or prescaler division ratio yet. ;----------------- Power-saving mode ------------------------------------ ; Power-saving mode enabled or about to be activated ? btfss OPT_PWRSAVE ; Power-save mode enabled (from config) ? goto PsNotBlanked ; Arrived here: power-saving is ENABLED through the config, ; but not necessarily ACTIVE at the moment . ; If power-save is already active, clear the display (may have 'flashed up') btfsc PSFLAG_ACTIVE ; if power-save already 'ACTIVE'.. call ClearDisplay ; then clear the display (latch) ; Next: Check if the frequency has changed significantly ; since the last 'reload' of the power-save timer. ; To keep things simple, only look at the LOW BYTES of the ; 'current' and the 'old' frequency reading at this stage ; (BEFORE multiplying the result with two power adjust_shifts) . ; 'psave_freq_lo' is an "old" reading; 'freq_lo' the current frequency. ; Both are UNSIGNED 8-bit values ! movfw freq_lo ; get low-byte of current frequency subwf psave_freq_lo, w ; W := freq_lo - psave_freq_lo ; Make the difference (new minus old frequency in W) positive : movwf bTemp ; bTemp := (freq_lo - psave_freq_lo) btfss bTemp,7 ; check the sign-bit (=MSB) goto PsDiffPos ; difference already posivite, else : comf bTemp,f ; bTemp := ~bTemp (for example, 0xFF -> 0x00) incf bTemp,f ; add one for two's complement PsDiffPos:; Arrived here: difference made positive, i.e. bTemp = abs(freq_lo - psave_freq_lo) . ; If the frequency-difference is 'quite high', ; turn off the flag PSFLAG_ACTIVE and clear the power-save-timer: movfw bTemp ; W := abs(freq_lo - psave_freq_lo) sublw PSAVE_MAX_DIFF ; W := PSAVE_MAX_DIFF - W ; C=0 if result negative (=large f-diff) btfsc STATUS,C ; skip next instruction if large frequency difference goto PsSmallDiff ; PsLargeDiff: ; Arrived here: there's a LARGE difference between 'current' and 'old' frequency bcf PSFLAG_ACTIVE ; Back to normal display mode clrf psave_timer ; restart 'power-save' activation timer (with display ON) movfw freq_lo ; set 'current' frequency as new 'old' frequency... movwf psave_freq_lo ; for the next XX-second interval ! goto PsNotBlanked PsSmallDiff: ; Arrived here: there's only a SMALL difference between 'current' and 'old' frequency . btfsc PSFLAG_ACTIVE ; power-save already 'ACTIVE' ? goto PsActive ; yes, already active -> check for flash-up ; Check the power-save timer; it may be time to turn the display OFF now : movfw psave_timer ; if(psave_timer > PSAVE_DELAY_TIME ) ... sublw PSAVE_DELAY_TIME ; subtract #PSAVE_DELAY_TIME - W -> C=0 if result negative btfsc STATUS,C ; skip next instruction if carry=0 (PSAVE_DELAY_TIME-W < 0) goto PsNoTimeout ; psave_timer still low, no 'timeout' yet ! ; Arrived here: Display was on, but almost no change in frequency -> enter power-saving mode movlw PSAVE_FLASHUP_TIME-1 ; let display flash up once before turning off movwf psave_timer ; ... to avoid overflow when incrementing it later bsf PSFLAG_ACTIVE ; set the flag 'power-save ACTIVE' to blank the display movfw freq_lo ; save low-byte of frequency when ENTERING power-save mode movwf psave_freq_lo goto PsSleep ; sleep for the first 600-millisecond-interval now PsActive: ; Here if power-saving mode already active . ; Check it it's time to let the display flash up for a short time ; to show the operator we're still alive ! movfw psave_timer ; if(psave_timer > PSAVE_DELAY_TIME ) ... sublw PSAVE_FLASHUP_TIME ; subtract #PSAVE_FLASHUP_TIME - W -> C=0 if result negative btfsc STATUS,C ; skip next instruction if (PSAVE_FLASHUP_TIME-psave_timer) < 0 goto PsSleep ; psave_timer still low, don't 'flash up' yet ! PsFlashUp: clrf psave_timer ; prepare timer for next period of darkness movfw freq_lo ; avoid turning the display on .. movwf psave_freq_lo ; .. if the VFO is only "slowly creeping" clrf psave_timer ; restart 'power-save' activation timer (with display OFF) goto PsNotBlanked ; and let the display flash up for one gate interval PsNoTimeout: ; small frequency difference, AND psave_timer still low.. ; Already in "power-save"-mode or normal display ? btfss PSFLAG_ACTIVE ; check the flag 'power-save ACTIVE' goto PsNotBlanked ; not set -> normal display (not blanked) ; Arrived here: 'Saving power', which means the display ; is blanked MOST of the time (but it may flash up every XX seconds ; to show the operator we're still alive) . PsSleep: call Sleep150ms ; put CPU to sleep for ~500 milliseconds.. call Sleep150ms call Sleep150ms goto CheckProgMode ; skip integer->BCD conversion (save power) PsNotBlanked: ; Display is not blanked for power-saving mode at the moment. ; If this 'absolute difference' is quite large, ; clear the power-save timer to prevent turning off the display ; within the next XX seconds : ; Reload the power-save-timer if there was a significant change ; since the last comparison. PrepDisp: ; Prepare the frequency (32-bit 'unadjusted' integer) for display: ; Multiply freq by 2^adjust_shifts to adjust for the prescaling ; WQS 2 frequency in Hz here ; and the timing period . The result will be a frequency in HERTZ, 32-bit integer. ; Note: the adjustment factor may be ONE which means no shift at all. tstf adjust_shifts bz NoAdjust Adjust: clrc rlf freq_lo , f rlf freq_ml , f rlf freq_mh , f rlf freq_hi , f decfsz adjust_shifts, f goto Adjust NoAdjust: ; WAS 3 ; Check the result against under- and overflow. ; (There should be none if the frequency didn't change too rapidly ; between the range-detection and the actual measurement ) movfw freq_hi ; underflow (freq = 0) ? iorwf freq_mh,w iorwf freq_ml,w iorwf freq_lo,w #ifndef RS232_OUT ; WAS this causes print to skip bz freq_underflow ; branch if yes #endif ; ! RS232_OUT btfsc freq_hi,7 ; overflow (freq > 7FFfffffh) ? goto freq_overflow ; branch if yes ; WAS 4 ; freq in freq_hi, freq_mh, freq_ml, freq_lo ???? ; 32 bit binary to BCD, display? ; Save the frequency value without offset for programming mode in 'freq2', ; because 'freq' will be lost when splitting it into digits. movfw freq_hi movwf freq2_hi movfw freq_mh movwf freq2_mh movfw freq_ml movwf freq2_ml movfw freq_lo movwf freq2_lo ; Add the programmable frequency offset ; (often used to add or subtract the intermediate frequency in superhet receivers) add32 freq, foffs ; freq := freq+foffs; 32-bit ; If the result is negative, make it posisive btfss freq_hi, 7 ; bit 7 of the most significant byte is the SIGN goto f_positive ; skip the following MACRO if positive.. neg32 freq ; freq := -freq (32-bit) f_positive: call CvtAndDisplayFreq ; Convert <freq> into BCD and show it on the display CheckProgMode: ; Arrived here, the frequency is still valid in 'freq2' ; but not in 'freq'. Poll the programming key, ; maybe the user wants to save this value as the new ; FREQUENCY OFFSET . #ifdef RS232_OUT ; no prog loop in RS232_OUT, no offset, just a frequency counter. goto MainLoop #endif ; RS232_out #if(DEBUG==0) btfss IOP_PROG_MODE ; Button "program mode" pressed ? goto EnterProgLoop ; Yes, enter programming mode ! #endif ; not DEBUG goto MainLoop ; end of main loop ;-------------------------------------------------------------------------- ; frequency underflow (frequency < 1Hz) ;-------------------------------------------------------------------------- freq_underflow: movlw BLANK ; display underflow as " 0[0]" call conv_char0 movlw BLANK call conv_char1 movlw BLANK call conv_char2 movlw 0 ; why not 'zero' in the last digit ? call conv_char3 movlw BLANK call conv_char4 ; because the 5th digit is OPTIONAL ! goto CheckProgMode ;-------------------------------------------------------------------------- ; frequency overflow (frequency > 50MHz) ;-------------------------------------------------------------------------- freq_overflow: movlw BLANK ; display overflow as " E" call conv_char0 movlw BLANK call conv_char1 movlw BLANK call conv_char2 movlw CHAR_E call conv_char3 movlw BLANK call conv_char4 ; Note that the 5th digit is OPTIONAL ! goto MainLoop ; end of main loop ;-------------------------------------------------------------------------- ; program loop : ; - show a simple menu to select ADD or SUBTRACT offset, ; - save the frequency offset value permanently in DATA EEPROM, ; - return to the main loop when done . ;-------------------------------------------------------------------------- ProgModeDisplay ; Subroutine to update the LED display in programming mode + delay movlw (PROGMODE_LOOPS)>>8 ; high byte for delay loops (usually 0.1 second) movwf gatecnt_hi movlw (PROGMODE_LOOPS)&0ffh ; low byte for delay loops movwf gatecnt_lo goto count_pulses ; update mux display + some delay + return PmDisp_Quit: ; show "quit" on first 4 digits (quit programming mode) movlw CHAR_Q call conv_char0 movlw CHAR_u call conv_char1 movlw CHAR_i call conv_char2 movlw CHAR_t PmDisp4: call conv_char3 ; for menu items with 4 characters movlw BLANK PmDisp5: call conv_char4 goto ProgModeDisplay PmDisp_PSave: ; show "PSave" or "Pnorm", depending on power-save flag btfss OPT_PWRSAVE ; Power-save mode active ? goto PMD_NoPwSave movlw CHAR_P ; if so, print "PSAVE".. call conv_char0 movlw CHAR_S call conv_char1 movlw CHAR_A call conv_char2 movlw CHAR_V call conv_char3 movlw CHAR_E goto PmDisp5 PMD_NoPwSave: ; else print "NoPSV" movlw CHAR_N call conv_char0 movlw CHAR_o call conv_char1 movlw CHAR_P call conv_char2 movlw CHAR_S call conv_char3 movlw CHAR_V goto PmDisp5 PmDisp_Add: ; show "Add " on first 4 digits (add frequency offset) movlw CHAR_A call conv_char0 movlw CHAR_d call conv_char1 movlw CHAR_d call conv_char2 movlw BLANK goto PmDisp4 PmDisp_Sub: ; show "Sub " on first 4 digits (subtract frequency offset) movlw CHAR_S call conv_char0 movlw CHAR_u call conv_char1 movlw CHAR_b call conv_char2 movlw BLANK goto PmDisp4 PmDisp_Zero: ; show "Zero" on first 4 digits (set frequency offset to zero) movlw CHAR_Z call conv_char0 movlw CHAR_E call conv_char1 movlw CHAR_r call conv_char2 movlw CHAR_o goto PmDisp4 PmDisp_StIF: ; show "taBLE" on first 4 digits (select standard IF) movlw CHAR_t call conv_char0 movlw CHAR_A call conv_char1 movlw CHAR_b call conv_char2 movlw CHAR_L call conv_char3 movlw CHAR_E call conv_char4 goto ProgModeDisplay PmDisp_IF_1: ; show 1st standard IF from table movlw EEPROM_ADR_STD_IF_TABLE + 4*0 goto PmLoadFreq2 PmDisp_IF_2: ; show 2nd standard IF from table movlw EEPROM_ADR_STD_IF_TABLE + 4*1 goto PmLoadFreq2 PmDisp_IF_3: ; show 3rd standard IF from table movlw EEPROM_ADR_STD_IF_TABLE + 4*2 goto PmLoadFreq2 PmDisp_IF_4: ; show 4th standard IF from table movlw EEPROM_ADR_STD_IF_TABLE + 4*3 goto PmLoadFreq2 PmDisp_IF_5: ; show 5th standard IF from table movlw EEPROM_ADR_STD_IF_TABLE + 4*4 goto PmLoadFreq2 PmLoadFreq2: ; Load <freq2> from EEPROM[w] and show it on the display movwf bTemp movlw freq2 ; load the ADDRESS of 'freq2' ... movwf FSR ; ... into the PIC's "pointer" register movfw bTemp ; and the EEPROM-internal offset into W call EEPROM_Read4Byte ; read <freq2> from EEPROM : *FSR = EEPROM[W] movlw freq2 ; load the ADDRESS of 'freq2' again ... movwf FSR ; ... into the PIC's "pointer" register call ShowInt32_FSR ; Splitt <*FSR> (32 bit integer) to 8 BCD-digits... goto ProgModeDisplay ; and show it for 0.1 seconds, maybe more ; "Execution" of the selectable menu items. Invoked after long key press. PmExec_Quit: ; quit programming mode (without changing anything) goto MainRestart PmExec_PSave: ; turn power-saving mode on/off movlw 0x01 ; bit0 = power-save xorwf options,f ; toggle Power-save flag in sofware-"options" register movlw options ; load the ADDRESS of 'options' ... movwf FSR ; ... into the PIC's "pointer" register movlw EEPROM_ADR_OPTIONS ; load the EEPROM-internal address offset (=destination) call SaveInEEPROM ; write *FSR into EEPROM[w] (bits 31..24) goto ProgModeDisplay PmExec_Add: ; add frequency offset from now on . ; This is achieved by saving the currently measured frequency ; in EEPROM memory and restarting the counter. SaveFreq2: ; save <freq2> (4 bytes) in the PIC's EEPROM memory : movlw freq2 ; load the ADDRESS of 'freq2' ... movwf FSR ; ... into the PIC's "pointer" register movlw EEPROM_ADR_FREQ_OFFSET ; load the EEPROM-internal address offset (=destination) call SaveInEEPROM ; write *FSR into EEPROM[w] (bits 31..24) incf FSR, f ; next source address please movlw EEPROM_ADR_FREQ_OFFSET+1 ; next destination address call SaveInEEPROM ; write *FSR into EEPROM[w] (bits 23..16) incf FSR, f ; next source address please movlw EEPROM_ADR_FREQ_OFFSET+2 ; next destination address call SaveInEEPROM ; write *FSR into EEPROM[w] (bits 15..8) incf FSR, f ; next source address please movlw EEPROM_ADR_FREQ_OFFSET+3 ; next destination address call SaveInEEPROM ; write *FSR into EEPROM[w] (bits 7..0) goto MainRestart ; restart with new frequency offset PmExec_Sub: ; subtract frequency offset from now on ; This is achieved by making 'freq2' negative (two's complement) ; and then saving it in EEPROM. neg32 freq2 ; freq2 := -freq2 (32 bit) goto SaveFreq2 ; save freq2 in EEPROM and restart PmExec_Zero: ; set frequency offset to zero clrf freq2_hi ; freq2 := 0 (32 bit) clrf freq2_mh ; ... medium high byte clrf freq2_ml ; ... medium low byte clrf freq2_lo ; ... low byte goto SaveFreq2 ; save freq2 in EEPROM and restart PmExec_StIF ; switch to "Standard IF selection mode" movlw MI_IF_1 PmExec_SetMI: movwf menu_index goto ProgLoop ; PmExec_SelIF ; Finished selecting a "standard IF" from table. ; Switch back to the main menu, and let ; the user decide if the offset is positive (add) ; or negative (sub). movlw MI_ADD ; Suggestion: ADD the offset goto PmExec_SetMI EnterProgLoop: ; Prepare 'program mode' : clrf menu_index ; Show "Prog" on the display movlw CHAR_P call conv_char0 movlw CHAR_r call conv_char1 ; show "Prog" on the display.. movlw CHAR_o call conv_char2 movlw CHAR_G call conv_char3 movlw BLANK ; Note that the 5th digit is OPTIONAL so we don't use it here call conv_char4 ; wait until the operator releases the "Prog" key, while display runs Enter2: call ProgModeDisplay ; update mux display + provide some delay btfss IOP_PROG_MODE ; Button "program mode" still pressed ? goto Enter2 ; yes, continue loop while displaying "Prog" ProgLoop: incf blinker, f ; Toggle the blink flag (for flashing for kHz-point) ; Show "quit", "add", "sub", "zero", ... on the display depending on menu_index (0..3) call PMDisplay ; show string[menu_index] on LED display (from table) btfsc IOP_PROG_MODE ; "program key" pressed now ? (low means pressed) goto ProgLoop ; no, wait until user presses it ; Arrived here, the key is PRESSED. The question is how long... ; A short press means "advance to the next menu index" , ; a longer press means "execute the selected function" . ; Everything under 1 second is considered a "short press". movlw .10 ; 10 * 0.1 sec movwf menu_timer ChkKey: btfsc IOP_PROG_MODE ; "program key" still pressed ? (low means pressed) goto ShortPress ; no, key released, it was a SHORT press (less than 0.5 seconds) call ProgModeDisplay ; wait another 100 milliseconds decfsz menu_timer, f ; decrement timer and skip next instruction if NOT zero goto ChkKey ; ; Arrived here, it's a LONG key press, but the key is still down.. ; Wait until the operator releases the "Prog" key ; Show a BLINKING display while the button is pressed, ; as an indicator for the user to release the button now. Release2: call ClearDisplay ; fill display latch with blanking pattern call ProgModeDisplay ; show blank display for 0.1 seconds call PMDisplay ; show string[menu_index] for 0.1 seconds btfss IOP_PROG_MODE ; Button "program mode" still pressed ? goto Release2 ; yes, wait for button release, otherwise.. goto PMExecute ; Execute the function belonging to menu_index ShortPress: ; advance to the next menu index, but don't execute the associated function movfw menu_index sublw MI_INDEX_MAX ; subtract #MI_INDEX_MAX - W register -> C=0 if result negative ("W too large") btfsc STATUS,Z ; skip next instruction if Z=0 goto LastMainMenu ; Z=1 means "this is the last item in the main menu" btfss STATUS,C ; skip next instruction if C=1 goto NotMainMenu ; C=0 means "this is not the main menu" incf menu_index, f ; menu_index := menu_index+1 goto ProgLoop ; end of programming loop LastMainMenu: clrf menu_index ; wrap to 1st menu index goto ProgLoop NotMainMenu: ; not main menu, but sub-menu .. movfw menu_index sublw MI_IF_SUBMENU_MAX ; subtract #MI_.. - W register -> C=0 if result negative ("W too large") btfsc STATUS,Z ; skip next instruction if Z=0 goto LastIfSubMenu ; Z=1 means "this is the last item in the main menu" btfss STATUS,C ; skip next instruction if C=1 goto NotIfSubMenu ; C=0 means "this is not the main menu" incf menu_index, f ; menu_index := menu_index+1 (in submenu) goto ProgLoop ; LastIfSubMenu: ; was in the last "standard IF submenu".. movlw MI_IF_1 ; back to the 1st standard IF submenu movwf menu_index goto ProgLoop NotIfSubMenu: ; was not in the "standard IF submenu".. clrf menu_index ; must be an error; back to main menu goto ProgLoop END ; directive 'end of program'

file: /Techref/microchip/freq2rs232-jp.htm, 114KB, , updated: 2010/4/12 12:30, local time: 2024/12/25 09:18,

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<A HREF="http://linistepper.com/techref/microchip/freq2rs232-jp.htm"> PIC 16F628 Frequency Counter with RS232 output in a DB9 backshell by Jan Panteltje</A>