collapseos/blk/595
Virgil Dupras 1a6a549857 Make the SPI Relay protocol support multiple devices
Working on programming AVR chips exposes a glaring omission in my
first design of the SPI Relay: not allowing multiple devices make
this task hard. I constantly have to unplug my SD card before, plug
the AVR chip holder, then play a bit, then unplug the AVR holder,
then replug the SD card...

My prototype for a SPI relay design is built, but I haven't tested
it yet. I need to adapt the code first, which is what I do here.

When the prototype is tested, I'll update the SDC recipe with a new
schema.
2020-09-17 09:48:55 -04:00

11 lines
445 B
Plaintext

SPI relay driver
This driver is designed for a ad-hoc adapter card that acts as a
SPI relay between the z80 bus and the SPI device. When writing
to SPI_CTL, we expect a bitmask of the device to select, with
0 meaning that everything is de-selected. Reading SPI_CTL
returns 0 if the device is ready or 1 if it's still running an
exchange. Writing to SPI_DATA initiates an exchange.
Provides the SPI relay protocol. Load driver with "596 LOAD".