Connection of DS90UB913A-Q1 & DS90UB914A-Q1 for HD Camera

Hello Kah Joo Lee,

If no pixel clock input is being sent into the 913A from the imager, then this is an issue with the imager. If no pixel clock input is provided from the imager (in PLCK mode or external oscillator mode) then the parallel imager data being sent to the 913A will not be synchronized and the system will not work.

a) Does the LVDS for Ser and Der will only be start to function (Connection be establish) and transfer the data when the Pixel Clock are input to the Serializer?

Answer: No, the Serializer and deserializer will function and send data over LVDS without the imager or SoC connected. This can be seen when a 913A EVM is hooked up by a cable to the 914A EVM - you will see LOCK and PASS go HIGH when a connection is established even without a pixel clock input from the imager. The reason for this is because there is an internal PLL that is generated inside the 913A chip - when no PCLK input is detected, the chip switches over to this internal oscillator which is ~ 50 MHz by default ( and can be changed through a register). Probing the PCLK output on the 914A IC will show this signal.

b) The I2C control signal cannot be transfer from Der to Ser or vice versa if there is no Pixel clock input to the Serializer?

Answer: The I2C control signals are independent of the pixel clock from deserializer to serializer - these signals are transferred over the backchannel. The I2C control signals are transferred within the forward channel payload from serializer to deserializer - even if no pixel clock input exists, I2C data will still be transferred from Ser to Des because the device will switch over to it's internally generated clock as mentioned above.

Regards,

Sean

Hi Sean,

Thanks for your replied.

Current we are making the working prototype base on TI Eval board as the board setup as reference from TI.

We have the Aptina demo board as well and we have the camera module using Aptina AR0132 + AP0100AT similar to TI design.

I've manage to powered and connect the LVDS Ser & Der and the PASS & LOCK was high with LED turn on.

However, when I connect the camera module + Serializer and connect through PoC to Deserializer+Aptina Demo board, the DevWare(Aptina image sensor Software) the software can't detect the Image sensor.

For the Image sensor module, the I2C are slave and and the DevWare Software (Aptina Demo Board) are Master of the I2C. At the DevWare Software start up, it will check for the image sensor by sending the I2C.

From your explanation, the I2C can be transfer only from Ser -> Der when there is no Pixel Clock?

So I2C cannot transfer from Der -> Ser to control the image sensor?

Can I said that, I need to pre-program the Image Sensor so that it can output the parallel data + Pixel Clock to Ser, so that the I2C can be transfer in bi-directional?

By the way, do your side have the setting and share to us how the demo set for (Aptina™ Automotive Camera Module) so that it can be view in Aptina's DevWare?

Thanks for your great support.

Hello Kah Jo Lee,

The I2C can indeed transfer data from DES --> SER to control the image sensor according to your setup above. It does not need the external PCLK applied from the Aptina image sensor to transfer I2C data over the backchannel (from DES --> SER). With the setup you have above, LOCK and PASS being HIGH is a good sign that everything is working properly between the 913A and 914A communication link.

The problem you are seeing is most likely an issue with the Aptina Demo2x base board. In order to obtain the software and settings to program the Aptina image sensor, you will need to contact Aptina directly.

-Sean

HI Sean,

1) I've set the image camera to have initialize data and output the picture data out from image sensor and able transfer fromTI Eval board of Ser -> Der output. However I've notice the Pixel Clock swing was not same as Pixel clock at Ser input side as picture below.

Pixel Clock input from image sensor to Ser:-

Output of Pixel Clock from Der without connect to any circuit from TI Eval board:-

What is the problem at the Der Pixel clock output?

How we can overcome this?

2) We need to have I2C to be communicate from Host to image sensor through Der -> Ser. What setting need to be done instead to have bi-direction I2C data transfer?

Thanks.

Hi Sean,

1) I've capture the PCLK from Eval board of 914A at the JP1 header. For the last post, I also probe the signal at the header pin of PCLK on the EVAL board as well. Does the PCLK are correct of signal are not reach 0V as shown?

2) I'll try a way to configure the I2C of the 914A.

Thanks.

Hello,

The PCLK image above from the 914A should be correct. There will be a small amount of DC offset on PCLK as verified in the laboratory.

-Sean