DS90UH941AS-Q1EVM: Connect to DS90UB948 and Set Up Registers

Hi Nick,

Are you trying to access remote registers from the 948 ALP side? If yes , this message is expected you can access the 941AS registers locally through the 941AS ALP profile and also can access the 948 registers remotely through the 941AS profile as well since the 948 is the downstream device connected to 941AS remote I2C. 

Accessing 948 remote register through 941AS ALP profile

if you want to access 941AS from 948 side you can use the scripting tab.

use devAddr for 941AS -- in my case it's 0x18. Reading device ID it gave me 24 or 0x18 in hex which is the expected value for 941AS ID. 

Regards,
Fadi A.

Hi Nick,

Can you give me more details on how you have the 941 and 948 configured ? Do you have them connected in single or dual FPD-Link mode? What PCLK are you using? What are the IDx addresses for the Ser/Des , and where are you trying to access I2C from? 

Can you send me a block diagram of your application including Ser/Des and point to me where you are trying to talk to the 948 from?
For now, let's establish the I2C communication to the 941AS locally. Open ALP and have it set to 941AS profile. In my case the EVM IDx is set to 0x18 - See table below.

This means that if I want to read the 941AS ID register 0x00 locally 

I would use the following python command in ALP scripting tab.
serAddr = 0x18
board.ReadI2C(serAddr,00)  #This will read out the value for register 0x00 for 941AS locally which in this case is 0x18.

The 948 IDx in my case is set to 0x58
So if I want to talk to it, I can use the same ALP scripting tab for the 941AS as well, but use the 948 IDx address instead of the 941AS IDx address to communicate with the Des side. 

For example: If I want to read out the general status of 948 from the 941AS scripting tab 

I would write the following code:
DesAddr = 0x58
board.ReadI2C(DesAddr, 0x1C)

If I want to write the value 0x01 to the 948 register 0x24 remotely through the 941AS scripting tab I would do the following:
board.WriteI2C(DesAddr, 0x24, 0x01)  

If I want to write 0xFA to the 941AS register 0x03 I would do the following:
serAddr = 0x18 # Device ID is set by IDX external strap voltage divider network. 
board.WriteI2C(serAddr,0x03,0xFA)

If you try above and still doesn't work.

Connect 941AS to 948 through the FPD-link channel and connect I2C to 941AS locally and send me a screenshot of your information tab of the 941AS. 

It should look something like this, only you should see DS90UB948 as the partner information vs. DS90Uh928 in below picture. 

Regards,
Fadi A.

Hi Nick,

I see, in this case you need to use the correct syntax to write to a 2-byte address as follows:

Regards,
Fadi A.