iCE40HX-8K

This is work in progress!

The iCE40 family of FPGAs by Lattice Semiconductor is quite interesting for beginners:

• Relatively cheap dev boards are available.
• 1k-8k LUTs is enough to do some some interesting things, even run a soft CPU like the Zylin ZPU or small RISC-V implementations.
• Lattice's "iCEcube2" design software is freely available.
• There's an opensource toolchain! Clifford Wolf managed to reverse engineer the bitstream and build up the toolchain. See http://www.clifford.at/icestorm/.

References:

• iCE40HX-8K breakout board product page

• Project IceStorm

• Running ZPU Softcore on Lattice ICE40, source code

• Messing with a iCE40HX-8K FPGA.

The physical constraint file for the iCE40HX8K Breakout board: ice40hx8k.pcf

Comparison

A (incomplete) list is mainatained by Lattice.

Notes:

• The icoBoard is designed as a FPGA based IO board for RaspberryPi. Most notably it has 8MBit of SRAM.
• The Zylin ZPU requires at about 2.5k logic cells/500 logic tiles so the iCE40HX-1K boards won't suffice for that.

Also interesting

• Dipsy sub-5$ UL1K breakout board.
• UPDuino Lattice iCE40-UP5K UltraPlus FPGA, 5.3k LUTs, 34 GPIO, 8$. (Within the iCE40 family the UP devices stand out because they have DSP blocks, hard SPI/I2C blocks, internal oscillators and 1MBit SRAM. Project Icestorm has experimental support.)

Breakout Board Overview

The images are taken from [1].

UART

Channel B of the FT2232H has a UART interface that is connectected to bank 0 of the iCE40:

Note that RX and TX are from the point of view of the FT2232H.

Testpoints

The board has 16 testpoints.

Hardware

TOTAL: $24.20

I/O

@todo

Rotary encoder

See the folder rotary_enc/.

Infrared

See the folder infrared/.

PLL

See the iCE40 sysCLOCK PLL Design and Usage Guide [8].

UART

See the folder uart/.

DAC

See the folder dac/.

ADC

See the folder adc/.

@TODO

Tools, Editors, IDEs

Atom (Mac OS X)

• Atom editor for Mac OS X.
  • The linter-verilog Atom plugin uses Icarus Verilog.
  • The language-verilog plugin adds syntax highlighting and snippets to Verilog files.
• Visual Studio Code is catching up but not quite there, yet (Dec 2017). E.g. there's no Icarus Verilog integration in any of the Verilog addins, yet.

IDEs

• APIO Experimental open source micro-ecosystem for open FPGAs
• APIO IDE for Atom editor.

Icarus Verilog

Icarus Verilog is a Verilog simulation and synthesis tool. It can parse Verilog 2005 (IEEE 1364-2005). Start here: http://iverilog.wikia.com/wiki/. On Mac OS X install with Homebrew:

brew install icarus-verilog

GTKWave

"GTKWave is a fully featured GTK+ based wave viewer for Unix, Win32, and Mac OSX which reads LXT, LXT2, VZT, FST, and GHW files as well as standard Verilog VCD/EVCD files and allows their viewing."

On Mac OS X install with Homebrew:

brew install homebrew/gui/gtkwave

References

• [1] iCE40-HX8K Breakout Board User's Guide - pdf
• [2] iCE40 LP/HX Family Data Sheet - pdf
• [3] FTDI FT2232H Dual High Speed USB to Multipurpose UART/FIFO IC - page, pdf
• [4] Micron N25Q032A13ESC40 32Mb, 3V, Multiple I/O Serial Flash Memory - page, pdf
• [5] Microchip 93LC56 2k 2.5V Microwire Serial EEPROM - , page, pdf
• [6] Linear Technology LT3030 Dual 750mA/250mA Low Dropout, Low Noise, Micropower Linear Regulator - page, pdf
• [7] Lattice iCE40 LP/HX/LM products page
• [8] iCE40 Development kits and boards page
• [9] iCE40 sysCLOCK PLL Design and Usage Guide pdf
• [10] iCEcube2 Design Software page
• [11] iCEcube2 2016-02 Tutorial pdf