DS90UB933-Q1: CRC disable

Shmuel Iliaich

Intellectual 310 points

Part Number: DS90UB933-Q1
Other Parts Discussed in Thread: DS90UB954-Q1, DS90UB953-Q1

Hi,

I'm working with video decoder with analog video (NTSC/PAL/SECAM) to 10 bit.

It doesn't have a CRC.

Does the DS90UB933-Q1 will neglect the data from the video decoder?

Thanks

over 4 years ago

0 Casey McCrea over 4 years ago

TI__Guru** 103215 points

Hello Shmuel,

933 samples up to 12 parallel data bits on the rising edge or falling edge of the input PCLK, and sends those across the link as received. It does not case about the data format. On the receiving end, if you are using 934 as the deserializer, then the same parallel data will be output on the other side unaltered.

If you are using a CSI-2 deserializer like DS90UB954-Q1, then the 933 input is required to have HSYNC/VSYNC signal inputs as well, so that the deserializer can use those signals to form packet boundaries for the CSI-2 packet output.

Best Regards,

Casey

0 Shmuel Iliaich over 4 years ago in reply to Casey McCrea

Intellectual 310 points

Hi Casey,

The deserializer is 960. The video decoder has HSYNC and VSYNC but no CRC. That might cause problem to the 933 because he has CRC chacking.

So can I disable the CRC at the 933?

Thanks

Shmuel

0 Casey McCrea over 4 years ago in reply to Shmuel Iliaich

TI__Guru** 103215 points

Hello Shmuel,

The CRC function you are referring to in the 933 is related to the FPD-link side, not the parallel DVP input side. The 933 does not do any sort of calculation or CRC check on the data which is coming in from the DVP source. It simply clocks in up to 12 parallel bits plus HSYNC/VSYNC on the rising or falling edge of the PCLK input and send those bits along to the other side.

Best Regards,

Casey

0 Shmuel Iliaich over 4 years ago in reply to Casey McCrea

Intellectual 310 points

Hi Casey,

Same question for the 953 connecting to 960.

I want to use ADV7182. It's analog to MIPI. the problem that this component doesn't have CRC at the MIPI output.

Is it a problem to 953 to get the data in the MIPI without CRC?

Thanks

Shmuel

0 Casey McCrea over 4 years ago in reply to Shmuel Iliaich

TI__Guru** 103215 points

Shmuel,

From what I can tell of the datasheet for ADV7182, it does not look like it converts to MIPI CSI-2. It looks like it converts to parallel DVP 8 bit (BT.656 with optional sync signals). So that component would connect to 933 instead of 953

There is no such thing as a CSI-2 interface which does not contain CRC. That is built into the MIPI CSI-2 packet structure and is mandatory for all CSI-2 devices to support.

Best Regards,

Casey

0 Shmuel Iliaich over 4 years ago in reply to Casey McCrea

Intellectual 310 points

Hi Casey,

My mistake, the component is ADV7280 .https://www.analog.com/media/en/technical-documentation/data-sheets/ADV7280.PDF

The question was regarding to it.

Thanks

Shmuel.

0 Casey McCrea over 4 years ago in reply to Shmuel Iliaich

TI__Guru** 103215 points

Hello Shmuel,

The ADV7280 looks suitable for connecting directly with DS90UB953-Q1

Best Regards,

Casey

0 Shmuel Iliaich over 4 years ago in reply to Casey McCrea

Intellectual 310 points

Hi Casey,

I know that ADV7280 is suitable for connecting to DS90UB953-Q1.

The problem is that ADV7280 doesn't have CRC.

Is it a problem for the DS90UB953-Q1?

Thanks

Shmuel

0 Casey McCrea over 4 years ago in reply to Shmuel Iliaich

TI__Guru** 103215 points

Hello Shmuel,

I don't know what you mean about the ADV7280 not supporting CRC. I don't see any information about that in the datasheet. Can you provide more detail on exactly what this means?

Best Regards,

Casey

0 Shmuel Iliaich over 4 years ago in reply to Casey McCrea

Intellectual 310 points

Hi Casey,

How the DS90UB953-Q1 will do with data in the MIPI without CRC?

Thanks

Shmuel

+1 Casey McCrea over 4 years ago in reply to Shmuel Iliaich

TI__Guru** 103215 points

Shmuel,

Again, I don't see any information in the datasheet for ADV7280 regarding it having no CRC functionality. Can you explain further what this means? Does that mean that the checksum field in the CSI-2 long packet format is all 0's? Does that mean that the long packet it truncated before the CRC field? What exactly does this mean? Because what you are describing does not make sense in the context of CSI-2. CSI-2 has a checksum (CRC) built into every long packet based on the MIPI protocol. If the source doesn't provide one, then its not really outputting CSI-2 and would not be able to pass any CSI-2 compliance testing. The point of CSI-2 is that is a standard protocol which guarantees interoperability between devices based on compliance to the standard.

Best Regards,

Casey

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DS90UB933-Q1: CRC disable