…if you remove the flash chip from the socket and use some other external device to send the initial configuration to the FPGA in ‘slave mode’, then the four SPI pins (SPI_SO, SPI_SI, SPI_SS_B and SPI_SCK) become available to the user application 49 clock cycles later - and that same external device can then take advantage of those IO!
these many things make me think of my homemade bridge diode…
Or one of those mililtary circuit board(Fallout junk items) ancient circuit board with no less than 50 of them on board
Wait. it work with SSD1306? @Mr.Blinky
If you can give me the sketch for NES controller (for a Arduino Micro), and @uXe figure out how to get one of your board to be, then I might be able to fit all these onto one Proto-shield. With a 3.5mm headphone jack.
That being what I am aiming for, but @uXe’s board is a tad too big.
The 8-pin IC is an SPI Flash memory chip - the specific one I used here is a A25L080. The FPGA automatically reads the ‘firmware’ from the flash chip and configures itself every time at power-up.
Basically, you just externally reflash that chip to load new firmware - or you can also pull the chip from the socket altogether and use the SPI pins that are exposed on that 8-pin footprint (plus RESET & DONE on the separate 2-pin header) to directly upload new firmware instead using a microcontroller (needs to be 3.3V!) or a Raspberry Pi for example…
Good explanation that helped me make sense of it here: