Part Number: TCA9548A
Hi,
I have this setup: FTDI master (ft4232h) connected to ADC (AD5593) through the mux, i'm selecting the relevant port and then sending command to the ADC.
I don't see that the output of the required port is toggling.
Attached is the snapshot of the signals when selecting the relevant port.
Is there something that i missed?
Thanks,I2C_Issue.zip
Lior,
The FTDI drivers seem to have an issue with properly issuing a stop condition.
In your zoomed out shot, you can see clock goes high and then data goes low and then high. I've recreated this on a mcu and debugged this same issue with another customer offline:
CH3 (purple): SD7
CH1 (yellow): Main SCL
Ch2 (Blue): Main SDA
Below is a typical I2C communication where a stop condition is issued by keeping the data line low after the second ACK and then releasing clock and then data shortly after.
Below I replicated the FTDI's stop condition (similar to your zoomed out image) which involves allowing data to go high then driving data low while clock goes high then back high again. You can see that my previous transaction received an ACK meaning CH7 should have been enabled but when I drive the data line low the SD7 (ch3) remains high. This means TCA9548A didn't execute the "FTDI's" command yet because it did not see a suitable stop condition.
Finally, I tried shifting the timing of when the data line goes low and the clock line goes high (you can see data goes low first now then clock goes high then finally data again). When I toggle SDA low, you can then see the SD7 (Ch3) go low.
To summarize, the FTDI's stop condition is not recognized by our device and requires a valid stop condition in order to properly enable the channels after a valid write transaction.
-Bobby
