DS90UB936-Q1: 936 can’t output signal with these two kinds of configuration

Amelie Zheng

Genius 10865 points

Part Number: DS90UB936-Q1

Hi Team,

My customer now use DS90UB936, and after the following two kinds of configuration. 936 still doesn't output signal...

Could you please give some advice? Thanks!

Configuration 1：

{0x4C,0x0F},
{0x1F,0x03},
{0x70,0x1E},
{0x7C,0xA0},
{0x4C,0x01},
{0x72,0xE8},
{0x33,0x01},
{0x21,0x14},
{0x20,0x20},

Configuration 2：

#Patgen Fixed Colorbar 1280x720p30
WriteI2C(0x33,0x01) # CSI0 enable
WriteI2C(0xB0,0x00) # Indirect Pattern Gen Registers
WriteI2C(0xB1,0x01) # PGEN_CTL
WriteI2C(0xB2,0x01)
WriteI2C(0xB1,0x02) # PGEN_CFG
WriteI2C(0xB2,0x33)
WriteI2C(0xB1,0x03) # PGEN_CSI_DI
WriteI2C(0xB2,0x24)
WriteI2C(0xB1,0x04) # PGEN_LINE_SIZE1
WriteI2C(0xB2,0x0F)
WriteI2C(0xB1,0x05) # PGEN_LINE_SIZE0
WriteI2C(0xB2,0x00)
WriteI2C(0xB1,0x06) # PGEN_BAR_SIZE1
WriteI2C(0xB2,0x01)
WriteI2C(0xB1,0x07) # PGEN_BAR_SIZE0
WriteI2C(0xB2,0xE0)
WriteI2C(0xB1,0x08) # PGEN_ACT_LPF1
WriteI2C(0xB2,0x02)
WriteI2C(0xB1,0x09) # PGEN_ACT_LPF0
WriteI2C(0xB2,0xD0)
WriteI2C(0xB1,0x0A) # PGEN_TOT_LPF1
WriteI2C(0xB2,0x04)
WriteI2C(0xB1,0x0B) # PGEN_TOT_LPF0
WriteI2C(0xB2,0x1A)
WriteI2C(0xB1,0x0C) # PGEN_LINE_PD1
WriteI2C(0xB2,0x0C)
WriteI2C(0xB1,0x0D) # PGEN_LINE_PD0
WriteI2C(0xB2,0x67)
WriteI2C(0xB1,0x0E) # PGEN_VBP
WriteI2C(0xB2,0x21)
WriteI2C(0xB1,0x0F) # PGEN_VFP
WriteI2C(0xB2,0x0A)

over 5 years ago

0 Hamzeh Jaradat over 5 years ago

TI__Guru** 107720 points

Hello Amelie,

How did they make sure there is no output signal even using the Pattern generator script?

If the have measured the CSI-2 outputs and still can't see anything, then there must be another issue on their board/design.

They need to check all power supplies on the 936 and make sure the device is operating normally!

0 bill chen over 5 years ago in reply to Hamzeh Jaradat

Prodigy 50 points

Hi Hamzeh Jaradat,

We have checked all the power supplies and the 24M XIN are ok. I2C read/write function are ok. But we don't have any test point for the mipi signal, so we can't measure these signal. Do we have other method to confirm if the chip is working ok, either in normal mode or test pattern mode?

0 Hamzeh Jaradat over 5 years ago in reply to bill chen

TI__Guru** 107720 points

Hello Bill,

can you check the following registers in the 936 during operation mode?

0x4D, 0x4E, 0x4F, 0x50, 0x58, 0x73, 0x74, 0x75, 0x76

0 bill chen over 5 years ago in reply to Hamzeh Jaradat

Prodigy 50 points

Hi Hamzeh Jaradat,

Registers dump result:

Configuration 1 (normal operation mode):
0x4D = 0x00
0x4E = 0x02
0x4F = 0x00
0x50 = 0x00
0x58 = 0x1a
0x73 = 0x00
0x74 = 0x00
0x75 = 0x00
0x76 = 0x00

Configuration 2 (test pattern mode):
0x4D = 0x00
0x4E = 0x02
0x4F = 0x00
0x50 = 0x00
0x58 = 0x1a
0x73 = 0x00
0x74 = 0x00
0x75 = 0x00
0x76 = 0x00

Seems the register value all the same in two mode.

0 Hamzeh Jaradat over 5 years ago in reply to bill chen

TI__Guru** 107720 points

Hello Bill,

from the provided register values I can see that the 936 is not receiving any Video data.

Normally you should have at least the value 0x03 in reg 0x4D and some numbers in the registers 0x73 - 0x76, but you have 0 in all of them.

Please investigate on your camera side to make sure it is streaming correctly!

0 bill chen over 5 years ago in reply to Hamzeh Jaradat

Prodigy 50 points

Hi Hamzeh Jaradat,

OK. For test pattern mode, these register value 0 are normal, right?

0 Hamzeh Jaradat over 5 years ago in reply to bill chen

TI__Guru** 107720 points

Yes correct! Using the pattern generator you are generating the signal internally, and you do not receive any data from Camera.

0 bill chen over 5 years ago in reply to Hamzeh Jaradat

Prodigy 50 points

Hi Hamzeh Jaradat,

For the pin FPDNLink RIN1- and FPDNLink RIN1-, are below resistors R481 and R480 necessary? If NC, will influence the main function?

0 Hamzeh Jaradat over 5 years ago in reply to bill chen

TI__Guru** 107720 points

Hello Bill,

Yes, the termination resistors (~50ohm) are very necessary! Without these you will have instability issues and lots of reflections.

Also the value of C577 and C581 shall be changed to ~ 50nF, otherwise inputs will be unbalanced and cause input signal issues.

0 bill chen over 5 years ago in reply to Hamzeh Jaradat

Prodigy 50 points

Hi Hamzeh Jaradat,

If we are using non-synchronous mode, the 50ohm resistors are still necessary?

0 Casey McCrea over 5 years ago in reply to bill chen

TI__Guru** 103215 points

Hello Bill,

Yes they are necessary - it does not depend on what clock mode is used.

Best Regards,

Casey

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DS90UB936-Q1: 936 can’t output signal with these two kinds of configuration