fpga logic analyzer

Due to the impracticality of using DDL's LA(logic analyzer) and the difficulty I encountered using the LA's interface, I decided to implement an LA on my own FPGA. Below are some prerequisites about for such an approach.

  • FPGA has 3.3V logic levels
  • Proficiency in VHDL/Verilog
  • Proficiency with Python or some frontend language
  • Proficiency with bash

I found a Logic Analyzer project by the name of SUMP2 written and maintained by Kevin Hubbard from Washington, USA. After a few emails with Kevin Hubbard. I was able to get the RTL LA backend on my HX8k FPGA and the Python frontend working. I document this process below.

Python Frontend Viewer

The [repository here] contains the RTL modified Python frontend as described below. There you will find installation instructions and configuration specifics for running SUMP2 on modern Macs. Here are a couple notes about changes I made.

Added "Darwin" to supported OS system - leaving system call behavior unchanged as MacOS terminal calls rarely deviate from those of Linux

if  self.os_sys != "Linux" and  self.os_sys != "Darwin":

And again on lines 2028, 2039, 2050, and 2178

if ( self.os_sys == "Linux" or self.os_sys == "Darwin"):

I also changed the default font for MacOS system to make it more readable - pygame doesn't seem to play nice with non-retina display

if(self.os_sys == "Darwin"):
    font_height = int( font_height, 20 ); # Conv String to Int
    font_height = int( font_height, 10 ); # Conv String to Int

Verilog Backend and Sump2 Protocol

It was necessary to make a number of modifications to the verilog to get it working with the Lattice HX8K. I originally used the proprietary ICEcube2 software to synthesize, time, layout, and verify my designs, but I quickly switched to the IceStorm toolchain by Clifford Wolf as it is much faster and reliable.

Assigning Pinouts

The sump2 verilog was designed for the Lattice HX1K icesticick board, so I first went through the HX1K's schematics while browsing through top.v. I had to hook up the FTDI ports to their respective pins on the HX8k. To do this, I referenced the HX8K schematics. I also assigned the status LEDs to their respective pins.

set_io clk_12m J3
set_io ftdi_wi B10
set_io ftdi_ro B12
set_io spi_sck R11
set_io spi_cs_l R12
set_io spi_mosi P11
set_io spi_miso P12
set_io LED1 B5
set_io LED2 B4
set_io LED3 A2
set_io LED4 A1
set_io LED5 C5
set_io LED6 C4
set_io LED7 B3
set_io LED8 C3