/** * Copyright (c) 2020 Raspberry Pi (Trading) Ltd. * * SPDX-License-Identifier: BSD-3-Clause */ // Example of reading/writing an external serial flash using the PL022 SPI interface #include <stdio.h> #include "pico/stdlib.h" #include "pico/binary_info.h" #include "hardware/spi.h" #define FLASH_PAGE_SIZE 256 #define FLASH_SECTOR_SIZE 4096 #define FLASH_CMD_PAGE_PROGRAM 0x02 #define FLASH_CMD_READ 0x03 #define FLASH_CMD_STATUS 0x05 #define FLASH_CMD_WRITE_EN 0x06 #define FLASH_CMD_SECTOR_ERASE 0x20 #define FLASH_STATUS_BUSY_MASK 0x01 static inline void cs_select(uint cs_pin) { asm volatile("nop \n nop \n nop"); // FIXME gpio_put(cs_pin, 0); asm volatile("nop \n nop \n nop"); // FIXME } static inline void cs_deselect(uint cs_pin) { asm volatile("nop \n nop \n nop"); // FIXME gpio_put(cs_pin, 1); asm volatile("nop \n nop \n nop"); // FIXME } void __not_in_flash_func(flash_read)(spi_inst_t *spi, uint cs_pin, uint32_t addr, uint8_t *buf, size_t len) { cs_select(cs_pin); uint8_t cmdbuf[4] = { FLASH_CMD_READ, addr >> 16, addr >> 8, addr }; spi_write_blocking(spi, cmdbuf, 4); spi_read_blocking(spi, 0, buf, len); cs_deselect(cs_pin); } void __not_in_flash_func(flash_write_enable)(spi_inst_t *spi, uint cs_pin) { cs_select(cs_pin); uint8_t cmd = FLASH_CMD_WRITE_EN; spi_write_blocking(spi, &cmd, 1); cs_deselect(cs_pin); } void __not_in_flash_func(flash_wait_done)(spi_inst_t *spi, uint cs_pin) { uint8_t status; do { cs_select(cs_pin); uint8_t buf[2] = {FLASH_CMD_STATUS, 0}; spi_write_read_blocking(spi, buf, buf, 2); cs_deselect(cs_pin); status = buf[1]; } while (status & FLASH_STATUS_BUSY_MASK); } void __not_in_flash_func(flash_sector_erase)(spi_inst_t *spi, uint cs_pin, uint32_t addr) { uint8_t cmdbuf[4] = { FLASH_CMD_SECTOR_ERASE, addr >> 16, addr >> 8, addr }; flash_write_enable(spi, cs_pin); cs_select(cs_pin); spi_write_blocking(spi, cmdbuf, 4); cs_deselect(cs_pin); flash_wait_done(spi, cs_pin); } void __not_in_flash_func(flash_page_program)(spi_inst_t *spi, uint cs_pin, uint32_t addr, uint8_t data[]) { uint8_t cmdbuf[4] = { FLASH_CMD_PAGE_PROGRAM, addr >> 16, addr >> 8, addr }; flash_write_enable(spi, cs_pin); cs_select(cs_pin); spi_write_blocking(spi, cmdbuf, 4); spi_write_blocking(spi, data, FLASH_PAGE_SIZE); cs_deselect(cs_pin); flash_wait_done(spi, cs_pin); } void printbuf(uint8_t buf[FLASH_PAGE_SIZE]) { for (int i = 0; i < FLASH_PAGE_SIZE; ++i) { if (i % 16 == 15) printf("%02x\n", buf[i]); else printf("%02x ", buf[i]); } } int main() { // Enable UART so we can print status output stdio_init_all(); #if !defined(spi_default) || !defined(PICO_DEFAULT_SPI_SCK_PIN) || !defined(PICO_DEFAULT_SPI_TX_PIN) || !defined(PICO_DEFAULT_SPI_RX_PIN) || !defined(PICO_DEFAULT_SPI_CSN_PIN) #warning spi/spi_flash example requires a board with SPI pins puts("Default SPI pins were not defined"); #else printf("SPI flash example\n"); // Enable SPI 0 at 1 MHz and connect to GPIOs spi_init(spi_default, 1000 * 1000); gpio_set_function(PICO_DEFAULT_SPI_RX_PIN, GPIO_FUNC_SPI); gpio_set_function(PICO_DEFAULT_SPI_SCK_PIN, GPIO_FUNC_SPI); gpio_set_function(PICO_DEFAULT_SPI_TX_PIN, GPIO_FUNC_SPI); // Make the SPI pins available to picotool bi_decl(bi_3pins_with_func(PICO_DEFAULT_SPI_RX_PIN, PICO_DEFAULT_SPI_TX_PIN, PICO_DEFAULT_SPI_SCK_PIN, GPIO_FUNC_SPI)); // Chip select is active-low, so we'll initialise it to a driven-high state gpio_init(PICO_DEFAULT_SPI_CSN_PIN); gpio_put(PICO_DEFAULT_SPI_CSN_PIN, 1); gpio_set_dir(PICO_DEFAULT_SPI_CSN_PIN, GPIO_OUT); // Make the CS pin available to picotool bi_decl(bi_1pin_with_name(PICO_DEFAULT_SPI_CSN_PIN, "SPI CS")); printf("SPI initialised, let's goooooo\n"); uint8_t page_buf[FLASH_PAGE_SIZE]; const uint32_t target_addr = 0; flash_sector_erase(spi_default, PICO_DEFAULT_SPI_CSN_PIN, target_addr); flash_read(spi_default, PICO_DEFAULT_SPI_CSN_PIN, target_addr, page_buf, FLASH_PAGE_SIZE); printf("After erase:\n"); printbuf(page_buf); for (int i = 0; i < FLASH_PAGE_SIZE; ++i) page_buf[i] = i; flash_page_program(spi_default, PICO_DEFAULT_SPI_CSN_PIN, target_addr, page_buf); flash_read(spi_default, PICO_DEFAULT_SPI_CSN_PIN, target_addr, page_buf, FLASH_PAGE_SIZE); printf("After program:\n"); printbuf(page_buf); flash_sector_erase(spi_default, PICO_DEFAULT_SPI_CSN_PIN, target_addr); flash_read(spi_default, PICO_DEFAULT_SPI_CSN_PIN, target_addr, page_buf, FLASH_PAGE_SIZE); printf("Erase again:\n"); printbuf(page_buf); return 0; #endif }

This firmware image was imported from the pico-examples repository. 


Copyright 2020 (c) 2020 Raspberry Pi (Trading) Ltd.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
   disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
   disclaimer in the documentation and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products
   derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.