Verilog : Simple I2C read operation

0
votes

I have written a program to read data from Microchip I2C EEPROM 24XX64. Initially I was able to get an acknowledge from the slave for command byte which indicates a READ operation. Perhaps, instead of data bits I was able to witness stL( write drive low signal) in model simulator. I would like to know the reason for this and what must be done to over come this signal.

1
verilog
Show us some waveforms and mark where you think things are going wrong! – Marty
Thanks for the reply. Please find the waveforms in the following link tinypic.com/r/2cr8qrb/6 – san6086

1 Answers

3
votes

To read from an I2C slave, you usually have to write the register address first. The process to read is:

  • START
  • Device Address + WRITE
  • Register Address (# of bytes depends on slave)
  • REPEATED START
  • Device Address + READ
  • Slave ACKs
  • Master Read bytes and NACKs when it's had enough
  • STOP

Did you do a write to set up a register address for the read?