SX Microcontroller Input / Ouput Methods for I²C

NEW! RS-232 / I²C-Adapter & Parallel I/O Module

Virtual Peripherals

• I²C Master Interface: This software works with the SX Demo Board provided by Parallax to write to, read from or erase the serial EEPROM memory device.
  • Source: i2cm_vp.src 19980603
  • Application Note: I2CM  PDF or CCS HTML
• I²C Slave Interface: This software works with the SX Demo Board provided by Parallax to write to, read from or erase the serial EEPROM memory device.
  • Source: i2cs_vp.src v1.01 19980814
  • Application Note: I2CS PDF or CCS HTML
• I²C Slave
  • i2c_slave.src v1.04a 20000329
  • Application Note: AN29 PDF or CCS HTML 20000919
• I²C Master
  • i2c_master.src v1.05a 20000516
  • Application Note: AN29 PDF or CCS HTML 20000919
• I²C Multi-Master
  • i2c_multi_master.src v1.06b 20000626
  • Application Note: AN29 PDF or CCS HTML 20000919
• I²C Dual-channel Multi Master 11/09/99
  • i2c_dual_multi_master.src¹ (...not sure this is the correct file content for this file. If you have a different copy, please email me)

Integrations:

• 19.2kbaud UART, two 8-bit A/D converters, two PWM outputs, one I2C serial link for EEPROMs, two 16-bit independent timers, Time clock (keeps count in msec), a software execution path switcher and push button detection and debounce. SX Demo Enhanced 2.0 by Craig Webb of Parallax Inc.
• 19.2k baud UART, two 8-bit A/D converters, two PWM outputs, one I2C serial link for EEPROMs, two 16-bit independent timer, and all implemented as Virtual Peripherals, in software. This is compatible with the SX Demo Board from Parallax, and is the same code is shipped with the Parallax Inc. tools.

Also:

• Virtual Peripheral Library
• Ubicom Virtual Peripheral Library - Interface section
• Non SX specific I2C

William Says:

I was debugging my project that uses an I2C EEprom and found a small bug in the example VP code. At the end of the I2CRead subroutine, after sending a Stop, the example code sends an ACK. This appears to cause the Start sent with the next command to fail, not a big deal since the Start is repeated again. The documentaton for the I2C EEproms, under READ OPERATIONS, states:

"... The 24xx00 will then issue an acknowledge and transmits the eight bit data word. The master will not acknowledge the transfer but does generate a stop condition and the device discontinues transmission (Figure 8-2). After this command, ..."

Comment out the 2 lines that send the ACK and it works fine:

:non_seq        JMP     Send_stop               ; no, signal stop & exit
; doc says "The Master will not acknowledge the transfer but does
generate a stop ..."
;		CLRB    out_bit                 ; yes, setup acknowledge bit
;		CALL    Write_bit               ;   and send it
		RETP                            ;leave and fix page bits