DS90UB941AS-Q1: 941 register values check, hud lose link

Hey Chen,

chen zh said:

 There is a issue that 941 can not connect hud (926) well, we can see always lose link from the log

What bit are you checking for link loss? I see reg 0xC = 0x47 so link is not lost here?

Also of these registers settings depend on which topology you are running and what settings you want to configure. I can't tell you that it's right based on reg dump alone. But I do see that you have Link established. Can you send me more details about this topology whether it's single or dual FPD link and what Pclk is used here. 
Also, please dump the registers twice so we can clear the transient errors. Send me 2nd register dump.

Regards,
Fadi A.

Hi

there are all regs value ,I dump again,please hele me to see there any isuue

addr: 0x00 data : 0x34
addr: 0x01 data : 0x0
addr: 0x02 data : 0x0
addr: 0x03 data : 0x9a
addr: 0x04 data : 0x0
addr: 0x05 data : 0x0
addr: 0x06 data : 0x58
addr: 0x07 data : 0x58
addr: 0x08 data : 0x5c
addr: 0x09 data : 0x1
addr: 0x0a data : 0x11
addr: 0x0b data : 0x0
addr: 0x0c data : 0x47
addr: 0x0d data : 0x30
addr: 0x0e data : 0x0
addr: 0x0f data : 0x0
addr: 0x10 data : 0x0
addr: 0x11 data : 0x0
addr: 0x12 data : 0x0
addr: 0x13 data : 0x9f
addr: 0x14 data : 0x0
addr: 0x15 data : 0x0
addr: 0x16 data : 0xfe
addr: 0x17 data : 0x1e
addr: 0x18 data : 0x7f
addr: 0x19 data : 0x7f
addr: 0x1a data : 0x1
addr: 0x1b data : 0x0
addr: 0x1c data : 0x7
addr: 0x1d data : 0x0
addr: 0x1e data : 0x6
addr: 0x1f data : 0x0
addr: 0x20 data : 0x0
addr: 0x21 data : 0x0
addr: 0x22 data : 0x25
addr: 0x23 data : 0x0
addr: 0x24 data : 0x0
addr: 0x25 data : 0x0
addr: 0x26 data : 0x0
addr: 0x27 data : 0x0
addr: 0x28 data : 0x1
addr: 0x29 data : 0x20
addr: 0x2a data : 0x20
addr: 0x2b data : 0xa0
addr: 0x2c data : 0x0
addr: 0x2d data : 0x0
addr: 0x2e data : 0xa5
addr: 0x2f data : 0x5a
addr: 0x30 data : 0x0
addr: 0x31 data : 0x9
addr: 0x32 data : 0x20
addr: 0x33 data : 0x3
addr: 0x34 data : 0xc
addr: 0x35 data : 0x0
addr: 0x36 data : 0x0
addr: 0x37 data : 0x0
addr: 0x38 data : 0x0
addr: 0x39 data : 0x0
addr: 0x3a data : 0x0
addr: 0x3b data : 0x0
addr: 0x3c data : 0x0
addr: 0x3d data : 0x0
addr: 0x3e data : 0x81
addr: 0x3f data : 0x2
addr: 0x40 data : 0x4
addr: 0x41 data : 0x5
addr: 0x42 data : 0x0
addr: 0x43 data : 0x0
addr: 0x44 data : 0x0
addr: 0x45 data : 0x0
addr: 0x46 data : 0x0
addr: 0x47 data : 0x0
addr: 0x48 data : 0x0
addr: 0x49 data : 0x0
addr: 0x4a data : 0x0
addr: 0x4b data : 0x0
addr: 0x4c data : 0x0
addr: 0x4d data : 0x0
addr: 0x4e data : 0x0
addr: 0x4f data : 0x8c
addr: 0x50 data : 0x16
addr: 0x51 data : 0x0
addr: 0x52 data : 0x0
addr: 0x53 data : 0x0
addr: 0x54 data : 0x2
addr: 0x55 data : 0x10
addr: 0x56 data : 0x80
addr: 0x57 data : 0x2
addr: 0x58 data : 0x3
addr: 0x59 data : 0x0
addr: 0x5a data : 0x49
addr: 0x5b data : 0x7
addr: 0x5c data : 0x7
addr: 0x5d data : 0x6
addr: 0x5e data : 0x44
addr: 0x5f data : 0x21
addr: 0x60 data : 0x22
addr: 0x61 data : 0x2
addr: 0x62 data : 0x0
addr: 0x63 data : 0x0
addr: 0x64 data : 0x10
addr: 0x65 data : 0x0
addr: 0x66 data : 0x0
addr: 0x67 data : 0x0
addr: 0x68 data : 0x0
addr: 0x69 data : 0x0
addr: 0x6a data : 0x0
addr: 0x6b data : 0x0
addr: 0x6c data : 0x0
addr: 0x6d data : 0x2
addr: 0x6e data : 0x20
addr: 0x6f data : 0x0
addr: 0x70 data : 0x3c
addr: 0x71 data : 0x70
addr: 0x72 data : 0x92
addr: 0x73 data : 0x88
addr: 0x74 data : 0x68
addr: 0x75 data : 0x0
addr: 0x76 data : 0x0
addr: 0x77 data : 0x5e
addr: 0x78 data : 0x74
addr: 0x79 data : 0x96
addr: 0x7a data : 0x8c
addr: 0x7b data : 0x6a
addr: 0x7c data : 0x0
addr: 0x7d data : 0x0
addr: 0xc2 data : 0x82
addr: 0xc3 data : 0x0
addr: 0xc4 data : 0x38
addr: 0xc5 data : 0x0
addr: 0xc6 data : 0x0
addr: 0xc7 data : 0x64
addr: 0xc8 data : 0x40
addr: 0xc9 data : 0x0
addr: 0xca data : 0x0
addr: 0xcb data :

Hi Chen,

Fadi is out of office this week. I'll be back with shortly.

Best,

Jack

Hi Chen,

Thank you for attaching the registers. I checked both register dumps and didn't find any difference. The reason we aren't seeing the link loss flag is because the TX_PORT_SEL (0x1E) is set for Port 1 and not Port 0. Please change TX_PORT_SEL (0x1E) on the 941 to 0x1 so we can analyze the registers for the HUD link.

Other hardware questions

• Is there a screen flicker when link is lost?
• How many systems are affected by link loss?

Best,

Jack

this register dumps is TX_PORT_SEL (0x1E) on the 941 to 0x1 

addr: 0x00 data : 0x34
addr: 0x01 data : 0x0
addr: 0x02 data : 0x0
addr: 0x03 data : 0x9a
addr: 0x04 data : 0x0
addr: 0x05 data : 0x0
addr: 0x06 data : 0x58
addr: 0x07 data : 0x58
addr: 0x08 data : 0x5c
addr: 0x09 data : 0x1
addr: 0x0a data : 0x10
addr: 0x0b data : 0x0
addr: 0x0c data : 0x47
addr: 0x0d data : 0x30
addr: 0x0e data : 0x0
addr: 0x0f data : 0x0
addr: 0x10 data : 0x0
addr: 0x11 data : 0x0
addr: 0x12 data : 0x0
addr: 0x13 data : 0x9f
addr: 0x14 data : 0x0
addr: 0x15 data : 0x0
addr: 0x16 data : 0xfe
addr: 0x17 data : 0x1e
addr: 0x18 data : 0x7f
addr: 0x19 data : 0x7f
addr: 0x1a data : 0x1
addr: 0x1b data : 0x0
addr: 0x1c data : 0x7
addr: 0x1d data : 0x0
addr: 0x1e data : 0x1
addr: 0x1f data : 0x0
addr: 0x20 data : 0x0
addr: 0x21 data : 0x0
addr: 0x22 data : 0x25
addr: 0x23 data : 0x0
addr: 0x24 data : 0x0
addr: 0x25 data : 0x0
addr: 0x26 data : 0x0
addr: 0x27 data : 0x0
addr: 0x28 data : 0x1
addr: 0x29 data : 0x20
addr: 0x2a data : 0x20
addr: 0x2b data : 0xa0
addr: 0x2c data : 0x0
addr: 0x2d data : 0x0
addr: 0x2e data : 0xa5
addr: 0x2f data : 0x5a
addr: 0x30 data : 0x0
addr: 0x31 data : 0x9
addr: 0x32 data : 0x20
addr: 0x33 data : 0x3
addr: 0x34 data : 0xc
addr: 0x35 data : 0x0
addr: 0x36 data : 0x0
addr: 0x37 data : 0x0
addr: 0x38 data : 0x0
addr: 0x39 data : 0x0
addr: 0x3a data : 0x0
addr: 0x3b data : 0x0
addr: 0x3c data : 0x0
addr: 0x3d data : 0x0
addr: 0x3e data : 0x81
addr: 0x3f data : 0x2
addr: 0x40 data : 0x4
addr: 0x41 data : 0x5
addr: 0x42 data : 0x0
addr: 0x43 data : 0x0
addr: 0x44 data : 0x0
addr: 0x45 data : 0x0
addr: 0x46 data : 0x0
addr: 0x47 data : 0x0
addr: 0x48 data : 0x0
addr: 0x49 data : 0x0
addr: 0x4a data : 0x0
addr: 0x4b data : 0x0
addr: 0x4c data : 0x0
addr: 0x4d data : 0x0
addr: 0x4e data : 0x0
addr: 0x4f data : 0x8c
addr: 0x50 data : 0x16
addr: 0x51 data : 0x0
addr: 0x52 data : 0x0
addr: 0x53 data : 0x0
addr: 0x54 data : 0x2
addr: 0x55 data : 0x10
addr: 0x56 data : 0x80
addr: 0x57 data : 0x2
addr: 0x58 data : 0x3
addr: 0x59 data : 0x0
addr: 0x5a data : 0x49
addr: 0x5b data : 0x7
addr: 0x5c data : 0x7
addr: 0x5d data : 0x6
addr: 0x5e data : 0x44
addr: 0x5f data : 0x21
addr: 0x60 data : 0x22
addr: 0x61 data : 0x2
addr: 0x62 data : 0x0
addr: 0x63 data : 0x0
addr: 0x64 data : 0x10
addr: 0x65 data : 0x0
addr: 0x66 data : 0x0
addr: 0x67 data : 0x0
addr: 0x68 data : 0x0
addr: 0x69 data : 0x0
addr: 0x6a data : 0x0
addr: 0x6b data : 0x0
addr: 0x6c data : 0x0
addr: 0x6d data : 0x2
addr: 0x6e data : 0x20
addr: 0x6f data : 0x0
addr: 0x70 data : 0x3c
addr: 0x71 data : 0x70
addr: 0x72 data : 0x92
addr: 0x73 data : 0x88
addr: 0x74 data : 0x68
addr: 0x75 data : 0x0
addr: 0x76 data : 0x0
addr: 0x77 data : 0x5e
addr: 0x78 data : 0x74
addr: 0x79 data : 0x96
addr: 0x7a data : 0x8c
addr: 0x7b data : 0x6a
addr: 0x7c data : 0x0
addr: 0x7d data : 0x0
addr: 0xc2 data : 0x82
addr: 0xc3 data : 0x0
addr: 0xc4 data : 0x18
addr: 0xc5 data : 0x0
addr: 0xc6 data : 0x0
addr: 0xc7 data : 0x64
addr: 0xc8 data : 0x40
addr: 0xc9 data : 0x0
addr: 0xca data : 0x0
addr: 0xcb data : 0x0

we also found that some times link ok ,but almost time lose link ,do you any suggestions?  

you question:

• Is there a screen flicker when link is lost?

         -----> no , black screen

• How many systems are affected by link loss?
• ----> only one at present

Hi Chen,

chen zh said:

we also found that some times link ok ,but almost time lose link ,do you any suggestions?  

This sounds like the link is marginal for this hardware. On the 926 ALP profile, there is a MAP (Margin Analysis Program) that will measure the link quality and give a visual indication. Are you able to directly connect to the 926 I2C bus?

MAP App Note: Link

I looked over the new 941 register dump. The only differences were not related to lock loss or the link. We will need to focus on the 926 side now.

Some other questions

• What cable length is used between the 941 and 926?
  • What's the cable connector?
• Have you tried different 941 and 926 module combinations?
  • Is it only the one HUD module that has link issues?

Best,

Jack