Commit Graph

4 Commits

Author SHA1 Message Date
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
Virgil Dupras
46676547d9 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 07:55:17 -04:00
Virgil Dupras
124da6adec 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.
2020-08-16 14:30:33 -04:00
Virgil Dupras
f09aa0603c rc2014: separate SPI relay and SDC drivers
My intention is to reuse the SPI relay to program AVR MCUs from a
RC2014.
2020-06-29 18:48:00 -04:00