applications/spi_flash_test/main.cc

// Copyright 2023 The Pigweed Authors
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.

#include <Arduino.h>
#include <cstdint>

#include <SPI.h>

#include "pw_log/log.h"
#include "pw_string/format.h"

// STM32 Port & pin          // PCB NET Name
const int ICE40Reset = PC13; // ICE_RST_N
const int ICE40Done = PC8;   // ICE_CDONE
const int FlashCS = PD2;     // ICE_SPI_SS
const int FlashHold = PC11;  // FLASH_HOLD
const int FlashWP = PC12;    // FLASH_WP
const int FlashMOSI = PB5;   // ICE_SPI_MOSI
const int FlashMISO = PB4;   // ICE_SPI_MOSI
const int FlashCLK = PB3;    // ICE_SPI_SCK
const int StatusLed = PB13;  // STATUS

int main() {
  Serial.begin(115200);

  // Put FPGA in reset.
  PW_LOG_INFO("Hold FPGA in reset");
  pinMode(ICE40Reset, OUTPUT);
  digitalWrite(ICE40Reset, LOW);
  delay(10);

  // Debug status LED
  pinMode(StatusLed, OUTPUT);
  digitalWrite(StatusLed, LOW);

  // SPI pin definitions
  pinMode(FlashCS, OUTPUT);
  digitalWrite(FlashCS, HIGH);

  SPI.setMISO(FlashMISO);
  SPI.setMOSI(FlashMOSI);
  SPI.setSCLK(FlashCLK);
  SPI.begin();

  char buffer[32];
  uint16_t update_count = 0;
  uint8_t manufacturer_id[4];

  while (true) {

    // Read the SPI Flash JEDEC ID.
    manufacturer_id[0] = 0x9f;
    manufacturer_id[1] = 0;
    manufacturer_id[2] = 0;
    manufacturer_id[3] = 0;
    SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE0));
    digitalWrite(FlashCS, LOW);
    SPI.transfer(manufacturer_id, 4);
    digitalWrite(FlashCS, HIGH);
    SPI.endTransaction();

    pw::string::Format(buffer, "SPI Flash JEDEC ID: %x %x %x",
                       manufacturer_id[1], manufacturer_id[2],
                       manufacturer_id[3]);
    PW_LOG_INFO("%s", buffer);
    delay(1000);

    update_count = (update_count + 1) % UINT16_MAX;

    // Toggle status LED each loop.
    if (update_count % 2 == 0) {
      digitalWrite(StatusLed, HIGH);
    } else {
      digitalWrite(StatusLed, LOW);
    }
  }

  return 0;
}