This special Core is intended exclusively for the FPGA-Companion firmware running on the Tang integrated onboard BL616 MPU use case.
It's a tool to display the debug console running at 2M Baud on a HDMI Monitor like a VT52 Terminal and communicate via Shell.
It might be useful to debug USB Hub or USB HID detect / compatibility issues.
By the way, you could also connect RX / TX pin of a USB-UART adapter + Putty or mincom to get identical results if you have one. See UART adapter. This project is intended for users who don't have such USB-UART adapter at hand.
It can be used also as template for Terminal based retro projects.
Prerequiste
You need to have FPGA-Companion for onboard BL616 µC installed on you Tang board.
Program the FPGA debug core that fit's to your Tang: bl616monitor_xyz.fs
Just connect the Tang board via a power feedthrough USB Hub (or TN20k bare +5V / GND) and have no other USB devices connected !
You will get a green color VT52 Terminal on your Monitor with some FPGA-Companion debug messages.
Connect a USB HID device like a Keyboard, Mouse, Joystick etc.
Each device shall generate a register message and show USB VID:PID etc.
You might need your mobile camera video function as messages arrive at tremendous speed and there is no scroll back.
A Joystick or Gamepad button/stick press will generate debug messages.
Keyboard / Mouse will not show any press/move message apart from initial registering.
You can enter with you keyboard commands like help or lsusb (lowercase)
Press Tang Button S2 to observe µC at boot time.
Press Tang Button S1 to open OSD.
| Signal | TN20k | TP25k | TM60k | TM138k Pro | Console 60k/138k |
|---|---|---|---|---|---|
| UART TX out | 48 | L6 USB-A + | tbd | B21 | R14 |
| UART RX in | 55 | N/A | tbd | C21 | P14 |
UART TX monitoring port is connected to USB-A positive pin. There is no UART RX monitoring port available.
In order that BL616 can receive on uart console there are HW modifications needed:
- Dock capacitor C22 need to be removed to avoid signal integrity issues.
- USB-A negative pin need to to be connected to the now freed C22 landing pad signal side. By that an extra connection in between FPGA and BL616 MPU is established (while the middle PMOD is still available for two Dualshock 2 gamepads or an retro D9 Joystick).
Uses sources from VT52