collapseos/blk/595

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. Sending any-
thing on SPI_CSLOW and SPI_CSHIGH is expected to select/deselect
the device, and writing to SPI_DATA is expected to initiate a
byte exchange. The result of the exchange is excpected to be re-
trieved by reading SPI_DATA.

You also need to define the exchange delay with SPI_DELAY. If
SPI clock is the same as system clock, 2 NOPs are enough:

: SPI_DELAY NOP, NOP, ;

Provides the SPI relay protocol. Load driver with "596 LOAD".
rc2014: separate SPI relay and SDC drivers My intention is to reuse the SPI relay to program AVR MCUs from a RC2014. 2020-06-30 08:48:00 +10:00			`SPI relay driver`

			`This driver is designed for a ad-hoc adapter card that acts as a`
Move SD Card subsystem outside of RC2014 recipe and add protocols Although the SPI Relay driver is RC2014-specific, the SD Card driver is generic enough to be a subsystem. That's the second subsystem we add and this warrants, I think, the formalization of a new concept: protocols. 2020-08-17 04:30:33 +10:00			`SPI relay between the z80 bus and the SPI device. Sending any-`
rc2014: separate SPI relay and SDC drivers My intention is to reuse the SPI relay to program AVR MCUs from a RC2014. 2020-06-30 08:48:00 +10:00			`thing on SPI_CSLOW and SPI_CSHIGH is expected to select/deselect`
Move SD Card subsystem outside of RC2014 recipe and add protocols Although the SPI Relay driver is RC2014-specific, the SD Card driver is generic enough to be a subsystem. That's the second subsystem we add and this warrants, I think, the formalization of a new concept: protocols. 2020-08-17 04:30:33 +10:00			`the device, and writing to SPI_DATA is expected to initiate a`
rc2014: separate SPI relay and SDC drivers My intention is to reuse the SPI relay to program AVR MCUs from a RC2014. 2020-06-30 08:48:00 +10:00			`byte exchange. The result of the exchange is excpected to be re-`
			`trieved by reading SPI_DATA.`

spi: add SPI_DELAY decl AVR chips often run at less than z80's system clock. This means that our SPI relay needs to have its own clock to properly communicate with it. This means that the delay between OUT and IN can't be hardcoded to 2 NOPs anymore. It needs to be configurable. 2020-08-23 21:55:17 +10:00			`You also need to define the exchange delay with SPI_DELAY. If`
			`SPI clock is the same as system clock, 2 NOPs are enough:`
rc2014: separate SPI relay and SDC drivers My intention is to reuse the SPI relay to program AVR MCUs from a RC2014. 2020-06-30 08:48:00 +10:00
spi: add SPI_DELAY decl AVR chips often run at less than z80's system clock. This means that our SPI relay needs to have its own clock to properly communicate with it. This means that the delay between OUT and IN can't be hardcoded to 2 NOPs anymore. It needs to be configurable. 2020-08-23 21:55:17 +10:00			`: SPI_DELAY NOP, NOP, ;`

			`Provides the SPI relay protocol. Load driver with "596 LOAD".`