mirror of
https://github.com/hsoft/collapseos.git
synced 2024-12-26 06:28:08 +11:00
1a6a549857
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.
11 lines
445 B
Plaintext
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".
|