from signal point of view, +3V3 is not mandatory. If I remember correctly, +3V3 on board side is to provide target Vdd voltage only, and user may connect on board 3.3V (target Vdd) via resistor (1k may be OK) to +3V3 pin of 2x2 header. then a short w...
You want 2x2 header with 1.27mm pitch. keying and polarity are preferred.something like TFM-102-01-L-D-WT may be considered.TFM-102-01-L-D-WT - High-Reliability Tiger Eye™ Terminal Strips, .050" Pitch | Samtec
some reference for QSPI/OSPI external flash loader for STM32H7 boards can be found here:stm32-external-loader/STM32H7x_boards at main · STMicroelectronics/stm32-external-loader · GitHub As you use STLINK as hardware programmer/debugger, and I suppose...
You may refer to an example for this board:STM32CubeH7/Projects/STM32H7B3I-DK/Examples/LTDC at master · STMicroelectronics/STM32CubeH7 · GitHub after the example is OK for your board, you may translate the source code to your desired style - only set...
You may start from a PWR_STANDBY example:STM32CubeF7/Projects/STM32F7508-DISCO/Examples/PWR/PWR_STANDBY at master · STMicroelectronics/STM32CubeF7 · GitHub