DS90UB949-Q1: How to access 928 internal Reg when 949-929 via single port1

Hello Haury,

Are you facing difficulties accessing the DES from the SER? This should be straightforward by only enabling the Pass-Through bit on the SER.

Hi Hamzeh,

Customer have tested the below configuration.

Reg 0x03=0x06 plus

test1. Reg0x1E = 0x02  => The address of 928 can be read in the Reg0x00

test2. Reg0x1E => 0x06 or 0x04 => The address of 928 can't be read in the Reg0x00

They also tried configure Reg 0x02 then configure Reg0x03.

But customer can't access 928 internal reg in all the upper configuration.

Could you give some suggestion for the detail configuration flow?

BRs

Haury

Hi Haury,

Are the devices linked and locked? It appears you are writing to some reserved bits on register 0x03 on the 949 which should be avoided. Also try checking the configuration of register 0x17 on the 949. 

Best Regards,

Melissa

Hi Melissa,

Melissa Chang said:

Are the devices linked and locked?

928 is locked and the display is normal.

Melissa Chang said:

It appears you are writing to some reserved bits on register 0x03 on the 949 which should be avoided.

Sorry for the typo. We write reg0x03=0x04(bit3=1) actually.

What should we write into reg. 0x17 for the function? Should we write bit7=1? 

What is the order in which the related registers are written?

BRs

Haury

Hi Haury,

Try this on the 949 and to see if you can communicate with the 928:

WriteI2C(0x18, 0x1e, 0x02)
WriteI2C(0x18, 0x03, 0x9A) 
WriteI2C(0x18, 0x17, 0x1E) 
ReadI2C(DES_ADDR, 0x00) 

Best regards,

Melissa

Hi Melissa,

The script doesn't work.

I find a similar thread in the below link. Could you help set up a bench test in the lab give me another script which have been verified?

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1118429/ds90ub947-q1-947-948-force-secondary-link-mode-single-link

BRs,

Haury

Hello Haury,

Today 2/20 is a US public holiday so the team will resume activity on 2/21. Thank you for your patience during this time 

Best Regards,

Casey 

Hi Haury,

I will try to get this setup in the lab tomorrow. In the meantime, what AC-coupling capacitor values are you using on both devices? 

Melissa Chang said:

what AC-coupling capacitor values are you using on both devices

I only have the value of 949 and it is 33nF. Pls see the sch of 949 as below.

HDMI转接板-598_1.pdf

I'll give you the update of 928 once I get the info.

BRs,

Haury