Send only slave address on i2c (no data)

Hi Max,

The behavior as mentioned in M24XX data sheet is not supported by Tiva I2C. However you can still do it by SW. In the code, you can ask for a Master Receive operation. If the I2C Slave NACK's then the master will terminate the transaction immediately on NACK. If the I2C Slave ACK's then the slave will send one data byte which can be flushed from the I2CMDR by a simple CPU read and a proper transaction initiated after that for Read or Write

e.g.

I2C master sends ADDR + R/W=1

if NACK try again

If ACK then wait for stop condition, Read the I2CMDR and junk the data

Now issue a proper data write or read from I2C Master

Regards

Amit Ashara

Hi Amit

Unfortunately to determine if the eeprom is busy is necessary a write operation (R/W=0).

Maybe sending 2 bytes is not a problem, but to do this I have another problem, described here.

best regards

max

Hi Max,

You can use the WC control to cause the Slave to NAK the Data and use the DATANACK MCS Status to terminate the operation and begin a fresh Write or Read operation

Regards

Amit Ashara

The WC pin is fixed to GND. However the EEprom will nak if it is busy.

best regards

Max

Hello Max,

If that is the case then the two scenarios as I see

1. If NACK then the data byte will be not be sent and STOP will be issued

2. If ACK then the data byte will be sent as Address and STOP will terminate it before the second ADDR byte is sent. A new transfer can be done to write to slave device

In both cases you should be able to program/read the slave device.

Regards

Amit Ashara