before buying a copy of the MKR Vidor 4000, it would be great if those already owning one could answer me the following, so that I know that I can use it:
- I'm still puzzled about how to get the FPGA bitstream into the FPGA. Can the FPGA load it from the attached flash memory chip? Or does it have to be uploaded from the MCU every time the board is powered up? If I get it correctly, the latter approach is followed by programs using the VidorGraphics library.
- If the answer to (1) is yes, is there a way to program the flash using the MCU? The VidorGraphics library appears to load the FPGA bitstream from the MCU, but what about write-through to the flash memory?
- If the answers to (1) and (2) are yes, are there example projects for uploading the flash memory content via Wifi? Since the Wifi components is an ESP32, there may be a way to program it as well?
- Oh, and I'm confused about the fact that the FPGA bitstream size is ~500 kB if I get it correctly, but the SAM MCU only has 256 kB internal Flash size. So how does this fit?
I don't find direct answers to these questions in the documentation, so it would be great if any of you could answer some or all of those. I'm currently comparing the MKR Vidor to the Spartan Edge Accelerator board from a different manufacturer, which follows a very different approach, though: They use an ESP32 MCU with 4 MByte Flash memory and a Xilinx FPGA that has no memory directly attached. So while the MCU needs to upload the Bitstream every time the board boots up, there is plenty of space for it. Implementing a Wifi access point program for the MCU to allow uploading the FPGA bitstream was not too difficult in that case. But the FPGA has no external RAM, which is a bit limiting for some projects (especially when using HDMI output, which both boards compared have).