DS90UB936-Q1: DS90UB936-Q1: Question about whether ds90ub953+ds90ub935 can be produced at the same time

Hi,

Please refer to the datasheet here. There are a few examples showing how CSI data received by the two FPD-Link RX ports can be combined to the same CSI output port. 

One consideration here is to ensure that the CSI payload fits in the bandwidth available on the port. 

Best,

Thomas

port 0:

Resolution 1920*1080 frame rate 30fps serializer -ds90ub935;

port 1:

Resolution 1600*1300 frame rate 30fps serializer -ds90ub953;

The output format of the two ports is YUV422-8bit(UYVY). I want to confirm whether the bandwidth can meet the requirements in this mode? thank you ~

Using the following set of registers, it can be achieved that a single group of using a certain port port, a single port data is successful; However, if the two ports are plugged into the camera at the same time, the data cannot be sent out; After measurement, the four mipi data lines of 936 have signals and are normal

/*disable built-in self test.*/
{0xb3, 0x00, 0x00},

/*Controls the CSI Transmitter frequency 800 Mbps*/
{0x1f, 0x02, 0x00},

/*RX_PORT_CTL 0x0C Port 0 & 1 both enable; any port lock or pass*/
{0x0c, 0xbf, 0x00},

/*======= begin SETUP PORT SEL RX0 0x4c ~ 0x7f 0xd0 ~ 0xdf=============*/
{0x4c, 0x01, 0x00},

/*FPD-Link III Input Mode CSI */
{0x6d, 0x7c, 0x00},

/*config back channel back channel frequency select.*/
{0x58, 0x5e, 0x00},

/*======= begin SETUP PORT SEL RX1 0x4c ~ 0x7f 0xd0 ~ 0xdf=============*/
{0x4c, 0x12, 0x00},

/*FPD-Link III Input Mode CSI */
{0x6d, 0x7c, 0x00},

/*config back channel back channel frequency select.*/
{0x58, 0x5e, 0x00},

/*config remote serializer i2c addr addr [7:1] 0x18 */
{0x5c, 0x30, 0x00},

/*enable RX port 0 & 1 forwarding*/
{0x20, 0x00, 0x00},

/*CSI VC MAP - Map value for VC-ID of 0*/
{0x72, 0x55, 0x00},

/*round robin forwarding*/
{0x21, 0x01, 0x00},

/*setup csi 4 lane ,Enable CSI output not continuous clk mode */
{0x33, 0x01, 0x00},

Hi,

Could you please clarify what error is observed when both FPD-Link RX ports are used? Additionally for bandwidth calculations here, could you share what the data type is for the two resolution sensors?

Best,

Thomas

One added comment, please make sure to set up CSI port, VCID re-mapping, forwarding mode, etc before enabling forwarding. Recommendations included below:

Thank you for your reply. In addition, the format of the two cameras is YUV422-8bit(UYVY).

hi~:

The relevant configuration has already been configured

Hi,

Thanks, for the data type. Could you please clarify what issue is observed when both ports are used? Are there errors in the CSI output? Or has the output been observed to be not present from the deserializer?

Best,

Thomas

hello :

At present, there is no problem observed when two ports are mapped at the same time. Would you like to ask which group of register values can be observed by reading? After measurement, the four lanes of mipi signal also have signals, do I need to upload mipi signal?

Hi,

Could you please clarify what the issue here is? From the above post my understanding was that there was a problem when both ports were mapped.

? ? said:

if the two ports are plugged into the camera at the same time, the data cannot be sent out

One helpful item would be to complete a register dump of both ports (one with 0x4C = 0x01 & one with 0x4C = 0x12

Best,

Thomas

HI:

The current problem is that the two ports of ti936 are configured according to the following figure: if the ti935 camera is plugged in separately, it can have data normally; Separately plug ti953 camera can also have normal data; However, if ti935 and ti953 are plugged in at the same time, there will be no data.

hi:

(one with 0x4C = 0x01 & one with 0x4C = 0x12) It's already set. but it does not works.

Hi,

Thanks or clarifying. Have we read back registers 0x73 - 0x76 on both ports to verify valid video data is present at the deserializer FPD RX?

Best,

Thomas

First of all, we would like to confirm: according to the ti936 datasheet, when the deserializer is DS90UB936-Q1, the serializer is ds90ub935 (port0) + ds90ub953(port1); The DS90UB936-Q1 cannot receive data streams from multiple sensors and cannot be multiplexed on the same CSI-2 link. Is that correct?

Hi,

I wouldn't expect this to cause a streaming issue such as you've reported here.

Best,

Thomas

hi ~

Thank you for your reply. If this is not the root cause, could you please help explain the meaning in the figure below? About 953 does not compatible

Hi,

The table noted above would not result in the issue you're seeing here. Please see the below recommendations for UB936:

1. Sequence of port enable is incorrect. Please enable CSI port (0x33) and set up forwarding mode (0x21 round robin) before enabling forwarding
2. Once the sequence is correct, please read back diagnostics during run time to confirm sensors are streaming. This will involve below registers for both RX ports (update 0x4C while reading back)
   1. 0x4D (RX port status 1)
   2. 0x4E (RX port status 2)
   3. 0x7A (CSI RX status on UB936)
   4. 0x73 - 0x76 (received line count and line length)

Without reading back diagnostics it's very challenging to isolate where an issue may be occurring.

Best,

Thomas

The CSI Transmitter frequency now is set to 800 Mbps，At this time, the bandwidth is not enough for the simultaneous transmission of two cameras, so it needs to be set to 1.6Gbps. I would like to ask which registers need to be configured when the CSI transmission frequency is set to 1.6Gbps?

Hi,

Please use the below register to update the CSI tx rate:

Best,

Thomas

The 0X1F register has been set to 0x00, but it is not working; Do I need to configure other registers besides this one？

Hi,

Have you read back any diagnostic registers as requested?

Thomas Bejin said:

Once the sequence is correct, please read back diagnostics during run time to confirm sensors are streaming. This will involve below registers for both RX ports (update 0x4C while reading back)

1. 0x4D (RX port status 1)
2. 0x4E (RX port status 2)
3. 0x7A (CSI RX status on UB936)
4. 0x73 - 0x76 (received line count and line length)

Best,

Thomas