Support Tang onboard BL616 µC for FPGA Companion / green LED fix

new Features:

• TC60K disable the green LED to save power and minimize light pollution. Now red LED in use.
• Support Tang Nano 20K onboard BL616 µC for the FPGA Companion firmware. Now optimized to ease FPGA re-programming
• Support Tang Console 60K onboard BL616 µC including the WIFI modem for the FPGA Companion firmware

Note

• Only newer Nano 20K types marking : 3921 are supported
• Console 60K +TN20K require an extern powered (see ->) USB Hub + USB-A to USB-A cable + USB-A Power Supply Plug

Warning

Important Console 60K FPGA programming note
Recommended to use Gowin 1.9.11.03 programmer toolset.
You have mandatorily to press the reconfigure button on top of the console plastics lid before programming.
Timing of button press or better say release is critical in success of the FPGA programming !
You have to give extFlash Program Go/Start immediately after release of the button otherwise programming will fail !

Background
The FPGA bitstream will reconfigure the programming JTAG pins into a SPI Interface and by that further programming attempts are blocked. Hardware connections in between onboard BL616 and FPGA are very limited and there is no other way than make use of both JTAG and UART signals to compile a proper SPI Interface with interrupt capability. For Tang Nano 20K the situation is different and JTAG chain can be kept intact all the time.

onboard BL616 µC
The BL616 µC enters programming mode when you keep the BOOT button pressed during a power-up (bottom left corner, close to one of the USB-C ports). You always can go back to factory default by just loading the bl616_fpga_partner_Console.bin firmware at address $0.