DS90UB941AS-Q1: Splitter mode design

Casey,

Thanks!

If 941 has been configured splitter mode ( and 941 0x00:0x2e, 0x06:0x58), does it mean that 941 can identify the 948? When the SOC is accessing 948, why the I2C between them always fail?

Every time when try to access 948, we will write 0x1e: 0x1 or 0x2 to choose the port.

Hi Casey,

Firstly, you can check 0x03 =0x9A as below.

Then could you help check the register configuration?

Below is the 948 configuration.

And below is the 941 configuration.

Please help us find if there is anything wrong.

Hello Hale,

First of all, the TSKIP_CNT seems low here. Is the DSI frequency really only 300MHz? For 2x 1920x720 I would expect it to be closer to ~500-600MHz. What is the DSI lane rate being used here?

In the 941AS configuration after enabling DSI with 0x01 = 0x00 I recommend to do the following:

Before enabling DSI with 0x01 = 0x00 set the following settings from section 10.2 of the datasheet:

After that set the following:

0x1E = 0x04 # Enable secondary I2C port 

Using address 0x2C set 0x03 = 0x9A # Enable I2C passthrough for port 0

Using address 0x2E set 0x03 = 0x9A # Enable I2C passthrough for port 1

Now you should be able to access the remote DES on port 0 and port 1 using address 0x58 and 0x78 respectively. You shouldn't need to set 0x17 = 0x9E

Best Regards,

Casey