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