ICEStick UART + packets encoding / decoding

Example UART project for Lattice icestick FPGA board. Supports PING & GET_INFO requests from master (in our case the linux PC).

Actual low level UART module is courtesy of https://github.com/cyrozap/osdvu.

Built with PlatformIO.

Usage

Build with pio run upload with pio run --target upload.

Compile C code with gcc pc-comm.c -o pc-comm and run with ./pc-comm to observe serial packets.

Send packets to FPGA with bash command:

• Get info: echo -en '\x08\x00\x00\x00\x00\x00\x00\x00' > /dev/ttyUSB2
• Ping: echo -en '\x00' > /dev/ttyUSB2

Both should return either pong or the info you can find harcoded in the uart_comm file:

• Pong: 0x01
• Get info response: 0x10 00 00 00 de ad be ef 13 37 0d 13 00 00 00 00

First byte of the packet is always the packet length, fourth byte is the message type and the rest is the payload.

Build stats

FPGA usage is the following:

IOs 8 / 96

GBs 0 / 8

GB_IOs 0 / 8

LCs 517 / 1280

DFF 166

CARRY 61

CARRY, DFF 0

DFF PASS 9

CARRY PASS 12

BRAMs 0 / 16

WARMBOOTs 0 / 1

PLLs 0 / 1