DS90UB940-Q1: DS90UB940 + DS90UB941 register configuration

jun long

Part Number: DS90UB940-Q1

Hi TI Teams,

we are using ds90ub941+ds90ub940 to convert DSI to CSI.

However, we currently encounter a problem that there is no signal output at the CSI output port of the ds90ub940, while DSI signals have been sent to 941.

We checked LOCK and PASS pin of 940 and found that LOCK is 1 and PASS is 0.

According to the spec of 940, it's said that when PASS is 0, it Indicates an error condition or corruption in display timing.

We dump regs of both 940 and 941 to compare with spec but can not determine the root cause of this issue.

We are using resolution: 480*854@60Hz, plase see detailed blanking timing as below:

h_active：480

hfp：20

hbp：20

hsync：10

htotal 530

v_active：854

vfp：40

vbp：40

vsync：10

vtotal 944

HW design: 2lane in dsi port0 on 941, single FPD-LINK III between 940 and 941(STP connect), 2lane in csi on 940. As below:

Please refer to attached files that including reg dumps of main reg and indiecr reg of 940 and 941:

Fullscreen ds90ub940_reg_configuration.txt Download

##ds90ub940寄存器dump
ds90ub941_partner_des_reg_dump_store:    00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
ds90ub941_partner_des_reg_dump_store: 00 58 04 00 e0 fe 1e 00 18 00 00 00 00 00 00 00 00
ds90ub941_partner_des_reg_dump_store: 10 00 00 00 00 00 00 00 00 00 01 00 00 23 40 00 00
ds90ub941_partner_des_reg_dump_store: 20 00 00 40 20 08 00 83 84 01 00 00 00 00 00 00 00
ds90ub941_partner_des_reg_dump_store: 30 00 00 90 25 01 00 00 8a 00 00 00 00 20 e0 23 00
ds90ub941_partner_des_reg_dump_store: 40 43 03 03 00 60 88 00 00 0f 00 00 08 00 00 63 00
ds90ub941_partner_des_reg_dump_store: 50 03 10 00 01 80 00 00 00 00 7f 20 20 00 00 00 00
ds90ub941_partner_des_reg_dump_store: 60 00 00 00 00 10 00 00 00 00 00 22 50 00 01 00 00
ds90ub941_partner_des_reg_dump_store: 70 00 00 00 07 07 08 00 00 00 00 00 00 02 00 00 00
ds90ub941_partner_des_reg_dump_store: 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ds90ub941_partner_des_reg_dump_store: 90 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ds90ub941_partner_des_reg_dump_store: a0 00 00 7d 00 00 00 00 00 00 00 00 00 00 00 00 00
ds90ub941_partner_des_reg_dump_store: b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ds90ub941_partner_des_reg_dump_store: c0 00 00 00 00 00 00 00 00 c0 00 00 00 00 00 00 00
ds90ub941_partner_des_reg_dump_store: d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ds90ub941_partner_des_reg_dump_store: e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ds90ub941_partner_des_reg_dump_store: f0 5f 55 42 39 34 30 00 00 00 00 00 00 00 00 00 00

##ds90ub940的CSI相关间接寄存器dump
ds90ub941_partner_des_csi_reg_dump_store:    00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
ds90ub941_partner_des_csi_reg_dump_store: 00 01 08 0b 0a 02 04 04 04 02 00 00 00 00 00 e0 81
ds90ub941_partner_des_csi_reg_dump_store: 10 00 00 00 3f 00 48 02 00 00 00 00 00 00 00 00 00
ds90ub941_partner_des_csi_reg_dump_store: 20 00 00 14 14 14 14 18 00 01 00 00 00 00 00 00 00

Fullscreen ds90ub941_reg_configuration.txt Download

##ds90ub941寄存器dump
ds90ub941_reg_dump_store:    00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
ds90ub941_reg_dump_store: 00 18 00 00 9a 00 00 58 00 00 01 17 00 47 30 00 00
ds90ub941_reg_dump_store: 10 00 00 00 89 00 00 fe 1e 7f 7f 01 00 00 00 01 00
ds90ub941_reg_dump_store: 20 0b 00 25 00 00 00 00 00 01 20 20 a0 00 00 a5 5a
ds90ub941_reg_dump_store: 30 00 09 00 05 0c 00 00 00 00 00 00 00 00 00 81 02
ds90ub941_reg_dump_store: 40 10 94 00 00 00 00 00 00 00 00 00 00 00 00 00 84
ds90ub941_reg_dump_store: 50 16 00 00 00 02 00 00 02 00 00 d9 00 07 06 44 1e
ds90ub941_reg_dump_store: 60 22 02 00 00 10 00 00 00 00 00 00 00 00 00 20 00
ds90ub941_reg_dump_store: 70 00 00 00 00 00 00 00 00 00 00 00 00 00 00 7f 00
ds90ub941_reg_dump_store: 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ds90ub941_reg_dump_store: 90 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ds90ub941_reg_dump_store: a0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ds90ub941_reg_dump_store: b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ds90ub941_reg_dump_store: c0 00 00 82 00 28 08 00 40 40 00 00 00 00 02 ff 00
ds90ub941_reg_dump_store: d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ds90ub941_reg_dump_store: e0 00 00 82 00 28 08 00 00 00 00 00 00 00 02 00 00
ds90ub941_reg_dump_store: f0 5f 55 42 39 34 31 00 00 00 00 00 00 00 00 00 00

##ds90ub941的DSI 0间接寄存器dump
ds90ub941_dsi_reg_dump_store:    00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
ds90ub941_dsi_reg_dump_store: 00 00 00 00 1d 14 12 00 00 00 00 00 00 00 00 00 13
ds90ub941_dsi_reg_dump_store: 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ds90ub941_dsi_reg_dump_store: 20 7f 00 ff 7f 00 00 00 00 00 00 3e 00 00 00 00 00
ds90ub941_dsi_reg_dump_store: 30 00 20 00 04 00 20 00 00 00 00 01 03 00 00 00 00

Thanks!

over 3 years ago

0 Fadi Abdulhameed over 3 years ago

TI__Mastermind 29555 points

Hi Jun,
Let's take a step back and try to run some internal PATGEN isolation to make sure that we have proper data path between the 941A and the 940. Once we establish that, we can move on the DSI debug as a next step, but for now.

1- Run PATGEN from the 940 side - check the output works as expected

2- Run PATGEN from the 941 side - check the output to verify that the link is established correctly and output works as expected.

As far as the DSI side - as an initial step, please see DSI bring up guide attached - This guide provides a bring-up flow to help with DSI source configuration and insight on how to resolve common system level problems when implementing a solution with DS90UB941

DS90UB941AS-Q1 DSI Bringup Guide.pdf

Regards,
Fadi A.

Interface

Interface forum

DS90UB940-Q1: DS90UB940 + DS90UB941 register configuration