Using the proprietary toolchain

Lattice Semiconductor provides a free license for Lattice Radiant, their latest CAD suite that supports the iCE40 FPGA. You can find more details in the official Lattice Radiant product page.

PDC file reference

Similar to the OSS toolchain, Lattice Radiant uses post-synthesis constraint files to map the design’s pinout to the physical chip. Following is an example .pdc pinout configuration file for the C0-microSD. You can create a new post-synthesis constraint file in your project by navigating to File -> New -> File, and selecting Post-Synthesis Constraint Files in the pop-up window.

#
#	Copyright (c) 2021 – 2024 Signaloid.
#	All rights reserved.
#

ldc_set_location -site {A1} [get_ports SD_DAT0]		# GPIO pin connected to the SD bus DAT0
ldc_set_location -site {A2} [get_ports SD_DAT1]		# GPIO pin connected to the SD bus DAT1
ldc_set_location -site {E5} [get_ports SD_DAT2]		# GPIO pin connected to the SD bus DAT2
ldc_set_location -site {F5} [get_ports SD_DAT3]		# GPIO pin connected to the SD bus DAT3
ldc_set_location -site {A4} [get_ports SD_CMD]		# GPIO pin connected to the SD bus CMD
ldc_set_location -site {B3} [get_ports SD_CLK]		# GPIO pin connected to the SD bus CLK

ldc_set_location -site {A5} [get_ports LED_GREEN]	# Green status LED
ldc_set_location -site {B5} [get_ports LED_RED]		# Red status LED

ldc_set_location -site {F1} [get_ports CONFIG_MOSI]	# MOSI pin of SPI configuration port
ldc_set_location -site {E1} [get_ports CONFIG_MISO]	# MISO pin of SPI configuration port
ldc_set_location -site {D1} [get_ports CONFIG_SCK]	# Clock pin of SPI configuration port
ldc_set_location -site {C1} [get_ports CONFIG_CS_N]	# Chip select of SPI configuration port (active low)
ldc_set_location -site {D3} [get_ports CONFIG_CDONE]	# Configuration done pin

Generating and flashing your custom bitstream

To generate the correct format of bitstream for your C0-microSD, select and edit your active strategy, navigate to the Bitstream section, and make sure that the Output Format option is set to Bit File (Binary). You can find details on how to flash your custom bitstream here.