Mecrisp Pi is a stack based FPGA co-processor, and Forth interpreter, for the RP2040 and RP2350 chips running on the Pico-Ice and (soon) Pico2-Ice circuit boards. Mecrisp Pi provides the Verilog and Mecrisp-Ice Forth to connect the two chips.
There are many differrent things you can build with Mecrisp-Pi:
- a Jupiter Ace style Forth Computer.
- Data Filters such as PDM to PCM.
- an RP2040/2350 coprocessor using the 8 FPGA DSP blocks.
- real time controller with many more I/O ports.
- very complex I/O devices.
The newer RP2350 chip in the pico2-ice can drive an DVI/HDMI display. Additional peripherals can be added with the pre-soldered pmods, no need to learn how to solder. The Mecrisp Ice Interpreter makes it much easier to debug your hardware designs.
Forth on the FPGA can access resources running on both cores of the RP chip. For example, MicroPython libaries can be used to drive the display. There are PIO programs which can act as USB host devices. There is software to run a FAT file system on the RP chip's FLASH, which can then be accessed from Forth on the FPGA. The ICE40 also has its own Flash which can be used for a block based file system.
The ICE40UP5k FPGA can also be used to accelerate parallel processes, or provides another 32 GPIO ports. 4 PMODS ports are available for additional functionality. For example, a Diligent I2S2 PMOD can provide stereo audio I/O.
This repository includes:
Compiled gateware for the J1a for the pico-ice FPGA.
Verilog definitions as well as additional useful modules in
./common-verilog.
Ready-to-emulate verilator simulators in ./verilator*
Cross compiler and the definitions of in ./common-crosscompiler.
An extended version of the Hayes-Forth test suite is located in
./testsuite. Some of the documentation is in german.
Pascal simulator is in ./common-crosscompiler.
You can either just flash the gateware or build it yourself.
First clone the repository
git clone https://github.com/PythonLinks/mecrisp-pi
cd mecrisp-pi/pico-ice
To flash the gateware on try:
sudo dfu-util -a 0 -D j1a.bin
To talk to the fpga, first you have to find the usb devices. On Ubuntu:
ls /dev | grep ACM
If there is /dev/ttyACM1 then in order to
get proper cr behavior on Ubuntu try:
picocom --imap crcrlf,lfcrlf /dev/ttyACM1
On Mac OS X I did
ls /dev | grep usb
And then:
picocom --imap crcrlf,lfcrlf /dev/tty.usbmodem1103
But I think that the current release of the pico-ice-sdk has problems on Mac Os. If you really need Mac OS, tell me, and I will try to debug the pico-ice firmware. I need it for myself anyhow.
First install gForth, freePascal, and OSS cad suite. Then
git clone https://github.com/PythonLinks/mecrisp-pi
cd mecrisp-pi
./compile
cd pico-ice
./compile
And then follow the above instructions for flashing and connecting.
To add your forth to the cross compiler, please edit this line in
pico-ice/compilenucleus.
cat ../common-forth/coredefinitions.fs basisdefinitions.fs ../common/double.fs ../common/fixpoint.fs ../common-forth/insight-16kb.fs > included.fs
If you have any problems, please send me an email. lozinski@PythonLinks.info
Or post an issue here.
Uart communication works.
This repository includes the gateware for spi communication between the RP2040 and the ICE40 FPGA. All it needs is your favorite firmware/language on the RP2040/RP2350. Since everyone wants a different langauge on the RP2040/RP2350 I leave that part in your good hands, and will be most happy to support you with the Verilog and Forth part. Details are in CDC.md.
If you have any questions, please join the Mecrisp-Pi Discord server