SN65DSI86: Required DSI endpoint or DSI to CSI conversion bridge chip details

Hi Gibin,

To answer your questions about the SN65DSI86:

•  Data rate - 2.5 Gbps
  
  Yes, this is supported. DSI86 resolution guide: https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1268829/faq-sn65dsi86-sn65dsi86-resolution-guide
  The maximum DSI data lane rate is 1.5 Gbps per lane, with 8 lanes maximum and maximum DSI clock rate supported is 750 MHz.

• support required for both DPHY and CPHY
  C-PHY is not supported for this device.
  
  
• compatible with DCS spec 
  
  DSC compression is not supported by the SN65DSI86. Is it required with this data rate of 2.5 Gbps? For a low video bandwidth it may not be required, but this depends on your application and requirements.
  
  
• should be able to read the frame crc
  There are error checking registers 0xF1 - 0xF0 which include checksum error bits for CRC error detection
  
  
• able to read DSI errors
  
  Please check the datasheet 0xF1 - 0xF8 registers for the common DSI error checking and related interrupts registers.
  
  
• able to decode DSC compressed data stream
  
  DSC compression is not supported
   

If the DSI and CSI-2 requirements are required for your device, I could check other solutions such as using DS90UB941AS-Q1 (DSI serializer) and DS90UB940-Q1 (CSI-1 desrializer). Please let me know if there are other options and topology/conversions that you could use in your system.



Best regards,
Ikram

1. please clarify whether IC is compatible with DCS spec. In the above response you provided answer for DSC not DCS 
2. Didnt get answer for Frame CRC . I am looking for CRC for the frame which is received by DSI RX , Not the packet CRC error 
3. Please share any alternative solution available for DSI to CSI conversion and DSI endpoint

Hi Gibin,

1. Sorry I previously misunderstood the question. According to this previous E2E thread DCS is supported by the DSI86: https://e2e.ti.com/support/interface-group/interface/f/interface-forum/681937/sn65dsi85-does-this-part-support-comversion-of-mipi-display-command-set-dcs-commands-to-display-ic

2. The only CRC error reported are the data stream CRC error on the packet processor. There is no DSI frame CRC error detection.


3. Depending on the video interface requirements, the DS90UB941AS-Q1 (DSI serializer) and DS90UB940-Q1 could be used for video conversion. Commonly these parts are used for automotive purposes for serializing and transmitting video data. Could you please check the datasheets to see if the video interface will meet your needs.

Thank you,
Ikram

i checked  DS90UB941AS-Q1 but i couldnt get details on how to validate the frame data with "DS90UB941AS-Q1" also . With this IC also is there any way to readback the pixel information or CRC available for the frame data ? How i can check the received  DSI packets are generating correct frame data?

Hello,

You are right that it does not have CRC error check on video frame data. Generally, you could also just check the DSI and DPHY errors described in the "8.3.1.3 DSI Errors and Status" section of the datasheet. And you can check the corresponding registers for the errors. 

Best regards,
Ikram

Hi ,

Want to check videoframe data also along with DSI errors . Is there any way to read the frame data using i2c or BTA from the IC memory ?

Regrds

Gibin

Hi, 

There is no specific register for CRC errors for frame data. We would suggest using the DPHY and DSI error checking which includes transmission errors.

You can also refer to this app note for bringup of the 941AS device: https://www.ti.com/lit/an/snla356/snla356.pdf

Best regards,
Ikram

HI ,

Along with DSI errors i want to verify the frame data is correct or not . Is there any way to read the frame data from the serializer using i2c or some other way

Hi,

Could you tell us what you mean by frame data? Are you trying to read pixel data within the frame?

If you are trying to read the actual pixel data then that would be done by the receiver sink dive from the deserializer output. It cannot be read directly from the SER or DES via I2C. 



Note: other than just the DSI errors, you could also check "DSI_VC_DTYPE" register for correct data type. And the app note shares the bringup flow to verify DSI configuration.

Best regards,
Ikram