DS90UB940-Q1: DS90UB940+DS90UB927 application

Hello Kailyn,

let me review all the provided details and come back to you within the next 2 days.

Hi Hamzeh,

Thank you very much for your reply.

Enable UB940 pattern generator, 0x64=0x05 to generate color bars, but the phenomenon is the same with extern input signal to UB927.

If 0x1B=0x7D,but it reads 0xB0, calculated PCLK=35.2Mhz.

 Below is the capture image with UB940 OFMT=0100 YUV420  and OFMT=0101 YUV422_8.

Best regards

Kailyn

Hello Kailyn,

It looks like you are using wrong timings not matching your display. Please double check the supported resolution and PCLK in your Display's datasheet.

Also, please refer to this Appnote for utilizing our Patgen.

Hello Hamzeh,

The RxCLKIN frequency of DS90Ub927 is 30Mhz. The CSI0 CLK of DS90UB940 is 105MHz

In addition,  MIPI CSI  signal of processor is by MUX 2:1 to select.  When it is selected UB954, the image captured is no problem. But MIPI CSI selected 927, it displays is abnormal. 

Best regards

kailyn

Hello Kailyn,

can you please plot a block diagram showing how are these devices, i.e. 927, 940 and 954 are related to each other? 

Hello Hamzeh,

 Below is the block diagram.  The DS90UB954 could capture image successfully , while DS90UB940+DS90UB927 appears the above problem. Please help.

Thank you very much.

Best regards

kailyn

Hello Kailyn,

Thanks for providing the block diagram. It is very helpful!

Are you sure your processor is receiving the same data from the 954 and from the 940?

What is the data type and resolution coming from the 954?

Can you also provide a register dump from the 940 CSI-2 indirect registers (0x00 to 0x2F)? You can dump these by writing the indirect register's address into main page register 0x6C, and then read main page register 0x6D.

Kailyn Chen said:

If 0x1B=0x7D,but it reads 0xB0, calculated PCLK=35.2Mhz.

Additionally, are you expecting the value 0x7D in reg 0x1B? because this means 135MHz which is not supported by the 927!

Kailyn Chen said:

Enable UB940 pattern generator, 0x64=0x05 to generate color bars, but the phenomenon is the same with extern input signal to UB927.

Are you using external CLK and timing for the patgen? If yes, can you repeat by using Internal CLK and timing from the 940.?!

Hello Hamzeh，

Thank you very  much for  your reply.

Hamzeh Jaradat said:

Are you sure your processor is receiving the same data from the 954 and from the 940?

They are not receiving the same data, the input of  933 is camera, the input of 927 is another processor.

Hamzeh Jaradat said:

What is the data type and resolution coming from the 954?

1280*720

Hamzeh Jaradat said:

Can you also provide a register dump from the 940 CSI-2 indirect registers (0x00 to 0x2F)? You can dump these by writing the indirect register's address into main page register 0x6C, and then read main page register 0x6D.

UB940 CSI-2 Indirect Registers:
Reg0x00=0x01
Reg0x01=0x08
Reg0x02=0x03
Reg0x03=0x0A
Reg0x04=0x02
Reg0x05=0x05
Reg0x06=0x02
Reg0x07=0x04
Reg0x08=0x02
Reg0x09=0x00
Reg0x13=0x3f
Reg0x14=0x00
Reg0x16=0x13
Reg0x2e=0x00

Hamzeh Jaradat said:

Additionally, are you expecting the value 0x7D in reg 0x1B? because this means 135MHz which is not supported by the 927!

The customer refers to the description of 0X1B to configure 0X7D, and read it 0XB0, by this he could calculate the PCLK frequency.

Hamzeh Jaradat said:

Are you using external CLK and timing for the patgen? If yes, can you repeat by using Internal CLK and timing from the 940.?!

He used the internal clock and it could output correct image.

Pattern Generator Indirect register：
Reg0x03=0x06;
Reg0x07=0x00;
Reg0x08=0x05;
Reg0x09=0x2d;
Reg0x04=0x50;
Reg0x05=0x05;
Reg0x06=0x32;
Reg0x0c=0x20;
Reg0x0d=0x20;
Reg0x0a=0x20;
Reg0x0b=0x20;
Reg0x0e=0x03;

Main register：
Reg0x6b=0x50;
Reg0x65=0x04;
Reg0x64=0x05;

and we could find that it is correct color bars.

Best regards

Kailyn

Hello Kailyn,

Kailyn Chen said:

UB940 CSI-2 Indirect Registers:
Reg0x00=0x01
Reg0x01=0x08
Reg0x02=0x03
Reg0x03=0x0A
Reg0x04=0x02
Reg0x05=0x05
Reg0x06=0x02
Reg0x07=0x04
Reg0x08=0x02
Reg0x09=0x00
Reg0x13=0x3f
Reg0x14=0x00
Reg0x16=0x13
Reg0x2e=0x00

I need the values of registers 0x0E to 0x12.

Kailyn Chen said:

He used the internal clock and it could output correct image.

That means the customer is using wrong Patgen or bad external clk for generating the patgen.

Please ask them do double check the 927 output. Also, make sure your 940 is using single FPD-Link mode for using that 30MHz pclk.

HI Hamzeh，

Thank you for your reply. 

UB940 CSI-2 Indirect Registers:
Reg0x0e=0x00
Reg0x0f=0x85
Reg0x10=0xff
Reg0x11=0xed
Reg0x12=0x0e

In addition, using UB927 pattern generator, if the 0x65=0x04 or 0x05,- the output color bar is correct. But if 0x65=0x00,the captured image is 

1280*20.

Best regards

kailyn

Hello Kailyn,

I have calculated your received data from the provided registers, it looks like the 940N is receiving the resolution 1280 x 665. Are these readings during Internal pattern generation or during external pattern generation?

Hello Hamzeh，

Thank  you very much for your reply.

The value of 0x0e-0x12 registers  is  read when during normal operation instead of pattern generation. 

Best regards

kailyn

Based on those readings, are you receiving the correct resolution, during normal operation?

Hello,

In the pattern configuration mentioned above, if the total horizontal line width is changed from 1360 to 1350, the image cannot be captured correctly; so adjust the timing of the actual image, HBP = 32,HT = 1360, Hspw=32, VBP = 32, VT = 800,VSPW=32, images can be captured correctly, why?

Another question that you would like to ask is that the if MODE_SEL0 and MODE_ SEL1 pulled down  and it could  capture images.

If I don't use the strap pin to configure, how to configure it by registers? I tried reg23=0x20, but it couldn't capture the image.

Below is the configuration when MODE_SEL0 and MODE_ SEL1 pulled down.

And this is the configuration by registers:

Best regards

kailyn

Hello Kailyn,

Let me go through this and get back to you.