CCS/TCA9548A-Q1: I2C deadlock risk

user3746678

Part Number: TCA9548A-Q1

Tool/software: Code Composer Studio

In my design ,a TCA9548A-Q1 is used. If one downstream port (eg. channel 0) SDA is always struck low (deadlock), whether the processor can access other channels normally? In other words, when one channel is deadlock , whether other channels and upstream port can work normally?

Thanks.

Gavin.

over 6 years ago

0 BOBBY over 6 years ago

TI__Guru* 79221 points

Hey Gavin,

If Ch0 SDA is stuck, you can try to toggle the SCL line. If this doesn't work, you would need to toggle reset on our TCA9548 and then you would be able to access the other channels (except for Ch0).

-Bobby

0 user3746678 over 6 years ago in reply to BOBBY

Intellectual 400 points

Hi, Bobby

Thanks for your answer. Can you tell me why TCA9548 can not access other I2C channels when Chennel o SDA is stuck.

Thanks

Gavin.

0 BOBBY over 6 years ago in reply to user3746678

TI__Guru* 79221 points

If Ch0 is enabled and is stuck low, that low is propagated to the main SDA line. Toggling reset would disable ch0 and the main SDA from seeing the stuck bus.

Alternatively, you could have the master detect the stuck bus then toggle the SCL line 9 or 18 times to see if the slave latching SDA low releases the SDA line.

-Bobby

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CCS/TCA9548A-Q1: I2C deadlock risk