For more info, reference USB bridge ch569 research
As we’re testing the CH569, we’ll need a way to connect this to the FPGA devkit, namely the T120 devkit. we’d want a board that connects to the devkit and output a usb 3 signal using the ch569.
The T120 devkit includes multiple ways to implement general GPIO, which is used to interface with the CH569. the IO connector, PMOD connector, and LVDS RX/TX can all be used for this.
Double check if there are limitations on these pins. ideally we’d want 32 GPIO pins to interface with the CH569, but 16 pins or 8 pins would also be fine. it might be easier to use the LVDS pins beacuse they are already length matched.
For more info, reference
VITUD (VI Tracker Usb Debugger) Research (FT2232H)
for space/weight constraints, we dont want to integrate a debugger on board for VITracker. the FPGA devkit includes a FT2232H for debugging.
instead, we’ll introduce a new debugger based on the FT2232H, kind of like the tigard: https://www.crowdsupply.com/securinghw/tigard
We don’t really want to pay for the tariffs and the extra features that it has, so we’d be working on a version where its built from scratch for VITracker.
Reference T120 devkit for more info. we’re likely going to use the tag connect series cable for connecting the debugger, or a 24 pin USB-C solution
We want to make this as cheap and small as possible. We should include just enough hardware that it would provide debug and serial console for VITracker. If it only costs a dollar or two to make it more universal, then make it universal.
| Requirement | Priority | Rationale |
|---|---|---|
| Compatibility with existing FPGA setup | 1 | simplifies debugging and eliminates a point of failure |
| External Quarts Crystal Clock | 1 | Reference clock for timing of FT2232H |
| Low profile interfacing with FPGA main board (eg. board to board/small connectors) | 1 | precious space saving on the main board. |
| EEPROM | 1 | Storing Config Data |
| Board to board connector to VITracker | 1 | allows a low profile connection while reducing the final footprint of VITracker |
| Small, compact | 2 | able to be mounted onto VITracker while its on a headset |
| USB-C interfacing with computer | 2 | Allowing the use of same connector as the main FPGA board |
| ESD Diodes | 2 | Prevent ESD damage on USB data pins |
| clean power input | 3 | reduces power related failures |