Z80-FPGA

Z80 CPU for OpenFPGAs, with Icestudio

Based on the iceZ0mb1e project by abnoname and the TV80 CPU

Quick start

Open the z80-soc-16KB-Boot.ice file with Icestudio
Connect the Alhambra-II board (or compatible) and upload the design
After 1 min aprox. the LEDs will show the value 0xAA
Let's upload a program test: open a terminal
Move to the roms folder
Execute the following line:

python3 z80-loader.py 05-counter.bin

After 2 seconds you will see a binary counter running on the LEDs
If you want to assemble that example, execute the following comands:

z80asm -o 05-counter.bin 05-counter.s

UART and pushbutton

The z80-soc-16KB-Boot-uart.ice file adds the following:

TX/RX Uart mapped in ports 0x10 (Data) and 0x11 (Status). The Data port is for transmitting (out) and receiving (in)
Input port 0x00. The SW2 button can be read from the bit 0 of port 0x00

Have a look at this examples for more details:

08-button-seq.s
UART-*.s