TCA6408A: How to understand INT resetting function ?

The /INT signal resets at the ACK or NACK after during a successful read from the port register. The I²C master issues an ACK if it wants to continue reading; it issues a NACK if the byte that was read is the last one. Any other NACKs belonging to other registers or devices have no effect. The reset happens just before the data byte is sent.

Hi below is a standard waveform, it shows the successful read, after the ack of repeat slave address, the INT reset. could you give me an example, what kind of NACK will reset INT ? please give me a clear wavefrom. i don't want to have unexpected INT reset.

1110100 is not the address of the TCA6408A. I guess that the /INT resets because the port input voltage changed back to the original value.

Hi Zhuangzhuang, 

Please check the addressing: 

Are there any changes to the port-side, like Clemens already commented? 

Regards,

Tyler

Hi, you are right, the waveform attached before is TCA9539A, I add TCA6408A waveform as below, the waveform is not critical, my key question is what kind of NACK will reset INT ? please give me a clear waveform. i don't want to have unexpected INT...