STM32 MIPI checksums

[Eetu Piukkula]

Posted on May 19, 2018 at 16:21

So, I am using STM32F769xxx to run MIPI-DSI display. On the display's datasheet there are power on and off sequences. I am able to get display on and off (so commands are at least somewhat OK), but colors and data on layer are totally messed up. I have good lead on that (wrong configurations as the display normally runs on 4 lanes, MCU has only 2 lanes, I have asked manufacturer about this, they should get back to me soon), but just in case I was wondering about packet footers (checksums).

Heres visual aid:

So, here's what this looks on code:

//SETEXTC

uint8_t pSETEXTC[4] = {0xB9, 0xFF, 0x83, 0x94};

HAL_DSI_LongWrite(&hdsi, 0x00, DSI_DCS_LONG_PKT_WRITE, 4, 0x3904002C, pSETEXTC);

HAL_DSI_Refresh(&hdsi); //Is this necessary?

How is that packet footer (PF) implemented on MCU? Do I need to calculate it manually and add two bytes of data at the end of pSETEXTC or does STMs DSI-interface do it for me? I read documents but it was not too clear about this.

Thanks in advence,

Eetu

[Tesla DeLorean]

Posted on May 19, 2018 at 17:09

'The Packet Handler schedules the activities inside the link. It performs several functions based on the interfaces that are currently operational and the video transmission mode that is used (burst mode or non-burst mode with sync pulses or sync events). It builds long or short packet generating correspondent ECC and CRC codes.'

[Eetu Piukkula]

Posted on May 19, 2018 at 17:17

Thank you. Solved