[Oberon] [EXT] RISC5 Project Oberon on Digilent's NexysA7
skulski at pas.rochester.edu
Thu Dec 24 05:39:21 CET 2020
>I have now similarly ported RISC5 Project Oberon to Digilent's Nexys A7-100T FPGA Trainer board:
Wonderful! It is a very nice board. I looked at the schematic and I have some questions.
>An onboard VGA socket
It is using 12 bits, 4 bits per R,G,B. In principle it can display 4k colors. It is rising the question how Project Oberon wants to handle color? A one-off Display per each board will lead to explosion of possible combinations. Are there any "official" plans to provide a universal color handling for Oberon System in general, which could be then customized to a particular palette: single bit B/W, four bit 16 colors, 8-bit pseudocolor with a lookup table, 12-bit color for Nexys, and other color depths for other boards?
> Additionally a USB keyboard (or USB mouse if preferred) can be used instead of one of the PS/2 connectors.
It is connected to a PIC micro. I wonder if the PIC code is available in source from Digilent or Microchip.
> Consequently only one of the four Pmod sockets needs to be used (for the remaining Pmod PS/2 connector).
In the reference manual says "Hub support is not currently available". I wonder whether "currently" means "forever".
>I'm getting some timeout issues when uploading files via the onboard SD card socket that I don't get with the Pmod SD card adapter.
The SD socket is connected to both the PIC micro and the FPGA. Perhaps there is some issue here, like additional loading of the SD signals by the PIC?
Thank you for doing all this!
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