Meanwhile I have soldered the unpopulated connector, next to the UART one on RPs mainboard. I can confirm that a JST 08FZC-SM1-GAN-TB(HF) fits perfectly. It can directly be ordered from JST.
While analyzing the port I have found out it exposes JTAG pins:
However:
- It's not full JTAG but SWD, a simplified one wire variant of JTAG.
- Only JTAG pins of MPU are available. It would be more interesting of having JTAG for ICU
- Readout protection seems to be activated as I wasn't able to read out anything from MPU. Thus I probably need to erase and reflash MPU firmware before I am able to use SWD features. As I don't want to brick it I won't do this right now.
- 3 pins are still unknown
Kinda interesting but seems not very useful to me yet.
While analyzing the port I have found out it exposes JTAG pins:
Code Select
1: SWCLK (3v3)
2: GND
3: SWDIO (3v3)
4:
5:
6:
7: VCC_MPU (3v3)
8: /RST (3v3)
However:
- It's not full JTAG but SWD, a simplified one wire variant of JTAG.
- Only JTAG pins of MPU are available. It would be more interesting of having JTAG for ICU
- Readout protection seems to be activated as I wasn't able to read out anything from MPU. Thus I probably need to erase and reflash MPU firmware before I am able to use SWD features. As I don't want to brick it I won't do this right now.
- 3 pins are still unknown
Kinda interesting but seems not very useful to me yet.