pico-ice-micropython

Micropython for pico-ice and pico2-ice from tinyVision.ai

To build

For riscv, you may add -DPICO_GCC_TRIPLE=riscv64-unknown-elf to the cmake command if your 'riscv64' compiler supports rp2350/rv32.

• git submodule update --init lib/micropython
• git submodule update --init lib/pico-ice-mpy-module
• cd lib/pico-ice-mpy-module && git submodule update --init pico-ice-sdk && cd ../..
• make -C lib/micropython/mpy-cross -j4
• make -C lib/micropython/ports/rp2 submodules
• cd boards/PICO_ICE
• mkdir build && cd build
• cmake -DPICO_BOARD=pico2_ice .. or cmake -DPICO_BOARD=pico_ice .. or cmake -DPICO_BOARD=pico2_ice -DPICO_PLATFORM=rp2350-riscv ..
• make -j8

Troubleshooting

• "Cannot find function pico_find_compiler_with_triples" This is a spurious pico-sdk error, if it happens, leave and delete the build directory, close your terminal, and repeat the process from mkdir.

To use

The API to use the FPGA is as follow:

• ice is the microypthon module: import ice
• fpga is the class provided by the module to manage the ICE40 FPGA ice.fpga(...)
• fpga provides the methods stop(), start(), and cram(file)

How to program a bitstream to the FPGA RAM

• The Pin class is imported from the machine module to provide interfacing with the hardware.
• The module is imported
• The fpga type is configured with the approriate pins for the device, as well as the frequency (in MHz) that the FPGA will run at.
• The bitstream file is opened, in byte (as opposed to text) mode (b), to read (r).
• The fpga is brought out of reset with fpga.start()
• The bitstream is loaded into the FPGA using fpga.cram(file) with the previously opened file as argument.

On pico-ice:

from machine import Pin
import ice
fpga = ice.fpga(cdone=Pin(26), clock=Pin(24), creset=Pin(27), cram_cs=Pin(9), cram_mosi=Pin(8), cram_sck=Pin(10), frequency=48)
file = open("bitstream.bin", "br")
fpga.start()
fpga.cram(file)

On pico2-ice:

from machine import Pin
import ice
fpga = ice.fpga(cdone=Pin(40), clock=Pin(21), creset=Pin(31), cram_cs=Pin(5), cram_mosi=Pin(4), cram_sck=Pin(6), frequency=48)
file = open("bitstream.bin", "br")
fpga.start()
fpga.cram(file)

How to program a bistream to the FPGA Flash (persistent bitstream)

On pico-ice:

from machine import Pin
import ice
file = open("bitstream.bin", "br")
flash = ice.flash(miso=Pin(8), mosi=Pin(11), sck=Pin(10), cs=Pin(9))
flash.erase(4096) # Optional
flash.write(file)
# Optional
fpga = ice.fpga(cdone=Pin(26), clock=Pin(24), creset=Pin(27), cram_cs=Pin(9), cram_mosi=Pin(8), cram_sck=Pin(10), frequency=48)
fpga.start()

On pico2-ice:

from machine import Pin
import ice
file = open("bitstream.bin", "br")
flash = ice.flash(miso=Pin(4), mosi=Pin(7), sck=Pin(6), cs=Pin(5))
flash.erase(4096) # Optional
flash.write(file)
# Optional
fpga = ice.fpga(cdone=Pin(40), clock=Pin(21), creset=Pin(31), cram_cs=Pin(5), cram_mosi=Pin(4), cram_sck=Pin(6), frequency=48)
fpga.start()