DS90UB948-Q1: GPIO8 abnormal on in 948+GPIO2/3 abnormal case in 948

Hi Alan,

Alan Xia said:

1. Harman found an abnormal case that GPIO8 of 948 will on for a short time after below code is implement done and we can’t avoid this spike plus now.

948 is a DES and the code you are showing is a SER code... not sure how the SER code is impacting your DES that's not possible. 

Alan Xia said:

When power on 948’s 3V3 power rail the GPIO2/3 will rise to 2.2V then drop to GND .

Are those GPIOs connected to anything? Seems like they are getting back-driven by another IC on your board. 

- Fadi A.

Hi Fadi，

Pls check：

1. Harman control 948 through 981 transient I2C path.
2. GPIO2/3 Has been disconnect to other IC ,  waveform is tested under float status.

Hey Alan,

Alan Xia said:

Harman control 948 through 981 transient I2C path.

1. Do you have logic analyzer of the I2C capture showing the issue?
2. How often does this fail?
3. Does this only happen on a single system or multiple systems?
4. What's the failure rate?

Alan Xia said:

GPIO2/3 Has been disconnect to other IC ,  waveform is tested under float status.

Can you send me the configuration of these GPIOs? Are you configuring these to passthrough any signal? 

Also, please send full schematic for review you can email it to me.

- Fadi A.

Hi Fadi，

Harman has shared the pythaon code for GPIO, including the SER side. Can you try to see if you can reproduce it on the EVM?

The customer also found an exception in GPIO7. We can discuss the relevant details in the loop of the email.

Hi Alan,

Where is the script gen and GPIO python code? 

- Fadi A.