RP2040 Control Software

Software to control GMM-7550 module on USB and USB 3 adapter boards.

Hardware platform: Adapter board, GMM-7550 and Memory extension.

RP2040 Command Line Interface

GMM-7550 Control CLI

Version    : 0.6.7
Git hash   : ee826e934eb3e670d5b96c27f85437bfc02c1601
Build time : 2026-01-13 18:34:57

> help

help:
 Lists all the registered commands

on
  Turn the GMM-7550 module ON

off
  Turn the GMM-7550 module OFF

hrst [0|1]
  Hard reset GMM-7550 module
  no argument - reset pulse
  0 - de-assert reset
  1 - assert reset

scan
  Scan I2C bus for available devices

pca
  Dump PCA9539A (I2C GPIO) registers

mux n
  Set SPI multiplexors. Useful settings:
    1 -- FPGA SPI
    2 -- NOR FLASH
    4 -- UART (SPI D2/D3)

cfg n
  Set Configuration mode. Useful settings:
    0 -- SPI Active
    4 -- SPI Passive
    c -- JTAG

rst [0|1]
  Soft reset GMM-7550 module
  no argument - reset pulse
  0 - de-assert reset
  1 - assert reset

pll [c|r|e|0|1|P0|Pa|Pb]
  PLL (CDCE6214) control (print help without an argument)

bootsel
  Reboot RP2040 into BOOTSEL mode (uf2 firmware update)

version
  Print RP2040 firmware version and build time information

2025-12-01 – basic functionality is implemented

• module power control
• hard and soft reset control
• FPGA configuration mode and SPI multiplexer control
• UART interface to the GMM-7550 module
• SPI inteface for FPGA configuration

Video of the GMM-7550 module controlled by RP2050 (Pico-based prototype) shows three demo FPGA projects:

• UART loopback (with LED activity indicator) loaded from on-board SPI NOR FLASH
• simple blinking LED demo
• more elaborate 8 LEDs light-show

LED demos are loaded from a host PC via USB/SPI inteface.