T48

WCH-link

Debug header

1. BO
2. 3V3

 * no 3.3V on PCB. I guess connect to WCH-Link 3V3?

1. SWDCLK
2. SWDIO
3. ground
4. BOOT

 * BOOT1?

Package pin assignment

• PA13/SWDIO
• PA14/SWCLK

boot to high pin => seems to enable USB even with SWD plugged in

Unbrick

In theory we have all firmware (system ROM, bootloader, main firmware) and should be able to unbrick devices. However, I was unable to restore my devices

Theory: unrick issue is firmware is not at correct .hex location. Things that didn't seem to work to get firmware .hex file:

 objcopy --input-target=binary --output-target=ihex --set-start 0x08000000 t48_bootrom_2022-06-30.bin t48_bootrom_2022-06-30.hex

 objcopy --input-target=binary --output-target=ihex --change-addresses 0x08000000 t48_bootrom_2022-06-30.bin t48_bootrom_2022-06-30.hex  

 objcopy --input-target=binary --output-target=ihex t48_bootrom_2022-06-30.bin temp.hex
 objcopy --change-addresses 0x08000000 temp.hex t48_bootrom_2022-06-30.hex