Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32F469/DSIHOST/DSI_GPDR#0x0
DSI Host Generic Payload Data Register
Payload Byte 1
Payload Byte 2
Payload Byte 3
Payload Byte 4
https://github.com/cmsis-svd/cmsis-svd-data