Dependencies

• FPGA Toolchain: https://github.com/YosysHQ/oss-cad-suite-build
• Simulator: https://verilator.org/guide/latest/install.html
• C++ toolchain: gcc and gnu make
• Trace Viewer: https://gtkwave.sourceforge.net/
• SPI flash programmer: https://www.flashrom.org/
• Linter: https://github.com/chipsalliance/verible
• Hardware research in dwfpy directory uses a Digilent Digital Discovery, python and the dwfpy library to probe and stimulate a MOS6532, for understanding expected behaviour from real hardware

Target Hardware

https://github.com/daglem/redip-riot

Programming the board using Raspberry Pi (3B) with flashrom

Wiring

Raspi pin name/num	ReDIP RIOT name/num
SCK / 23	SPI_SCLK / 3
MISO / 21	SPI_SIO1 / 5
MOSI / 19	SPI_SIO0 / 7
CE0 / 24	SPI_CS / 1
GPIO25 / 22	CDONE / 2
3v3 / 17	3v3 / 8
GND / 20	GND / 6
GPIO24 / 18	CRESET / 4

make MCS6530_002=1 # build the project
scp build/mcs6530.bin pi@<your-pi's-ip>: # copy the build artifact to the pi for flashing
ssh pi@<your-pi's-ip> # connect to the pi
sudo raspi-config # go into the interfaces menu and enable spi after running this command
pinctrl set 24 op dl # put the board into programming mode by setting creset low
flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=20000 # if this detects the device, all is good, otherwise check your spi is enabled and your wiring
truncate -s 128K mcs6530.bin # pad the rom to 128K
flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=20000 -w mcs6530.bin # write the flash
pinctrl set 24 ip pu # exit programming mode by returning creset to input pullup

Building and running the simulation tests

make MCS6530_002=1 sim
./obj_dir/Vverilator_top # this will throw assertion errors if the tests fail

Also you can examine the logic signals output during the test in the Vverilator_top.vcd file using GTKWave