Z80 ICE

I had problems with the USB UART (CH340G). It frequently disconnected under Linux.

I just looked into this these past weeks. It turned out that the USB connector became flaky and that was the cause for the frequent disconnects. I also suspected the chip wasn't supported, but a loopback test worked fine with minicom (while the connection lasted). So linux supports the CH340G.

The binary editor was a bit awkward to use. I simplified this and added the terminal's arrow keys to move around.

How to use: 

like shown in the photos, the STM32F407GT6 board is plugged into a STM to Z80 adapter board.

This board makes the connection to the serial port of the STM board and a connector is available to connect an FTDI basic or similar USB to serial converter. Open a terminal at 115200 bauds N81, and set ANSI terminal.

There was a compilation error that was simple to correct. In Core/Src, there's a file sysmem.c. Edit it and add this include:

#include <sys/types.h>

A minor fix to display the status of the debugger: Step, Run or Halted.

I completed the debugger: it can step, run until 'RET', run until PC = address, run continuously. You can also edit the registers between steps.

Importing symbols will be implemented later.

https://github.com/jpelletier/Z80_ICE

I'm currently writing the debugger part of the Z80 ICE. I would like to have suggestions and features that users would want.

-step

-step until return

-breakpoint (step until PC = breakpoint address)

More complex features to implement:

support for NMI and interrupts, (being able to step in these)

import symbol files from SDCC and Z88SDK

I just integrated the libZ80 and it now executes Z80 code!

I will make a easy to use debugger which can step, show disassembly, registers and stack.

To do: import symbol files

Adjusted the bus cycles timing to be equivalent to those measured on a real Z80 at 4 MHz.

Done some improvements to the binary editor, it's a bit easier to use and there's now a help on screen.

The Intel Hex loader now works if we send bytes slowly enough. On linux, I use the command: "pv -L 10 myhexfile.hex > /dev/ttyUSB0", which transmit 10 bytes/sec.

I will try to implement interrupt or DMA on the serial port.