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Driver: SPI Master¶

1 功能概述¶

该sample演示了SPI作为Master对开发板上的Flash进行读写操作。

2 环境要求¶

PAN1080 EVB 一块
USB-TypeC 线一条（用于供电和查看串口打印 Log）
硬件接线：
- 使用 USB 线，将 PC USB 与 EVB USB-TypeC（USB->UART）相连
- 使用杜邦线将 EVB 上的:
  - TX0 与 P00 相连
  - RX0 与 P01 相连
PC 软件: 串口调试助手（UartAssist）或终端工具（SecureCRT），波特率921600

3 编译和烧录¶

例程位置：zephyr\samples_panchip\drivers\spi_master

使用 ZAL 工具可以对其进行编译、烧录、打开 VS Code 调试等操作。关于 ZAL 工具的详细介绍请参考：Zephyr APP Launcher 工具介绍。

4 演示说明¶

连接SPI引脚到Flash模块（开发板上进行跳线）。

==注：请注意开发板上引脚共用问题，不要将下面四个引脚跳线至其他模块==

引脚

功能

P02

CS

P03

SCK

P30

MOSI

P31

MISO
此例程支持DMA，选择prj_dma.conf编译即使用DMA的方式进行SPI通信。

Sample执行流程：

擦除0地址开始的一个page

读取一个page数据，检查是否擦除成功

从0地址开始写入256byte的随机数据

从0地址开始读取256byte数据并且和之前写入的数据做比较，检查是否写入成功

程序正确执行时，日志界面如下：

SPI Master 例程Log¶

5 开发说明¶

5.1 启用SPI模块¶

在prj.conf文件中添加“CONFIG_SPI=y”启用SPI模块。如需使用DMA则需要添加“CONFIG_SPI_PANCHIP_DMA=y“。

CONFIG_SPI=y
CONFIG_SPI_PANCHIP_DMA=y

5.2 初始化SPI¶

const struct device *spi = DEVICE_DT_GET(DT_NODELABEL(spi0));
if (!device_is_ready(spi)) {
    printk("SPI device %s is not ready\n", spi->name);
    return;
}

5.3 SPI配置¶

可根据实际情况配置即可，需要注意的是参数frequency指的是时钟的分频系数，并非实际的时钟数。例如当前系统外设时钟为16MHz，frequency配置为4，则SPI的时钟速率为16/4=4MHz。

5.4 写操作¶

实现向slave写数据

struct spi_buf bufs[] = {
    {
        .buf = data,
        .len = len
    },
};
struct spi_buf_set tx = {
    .buffers = bufs,
    .count = 1
};

/**
 * @brief Write the specified amount of data from the SPI driver.
 *
 * @note This function is synchronous.
 *
 * @note This function is an helper function calling spi_transceive.
 *
 * @param dev Pointer to the device structure for the driver instance
 * @param config Pointer to a valid spi_config structure instance.
 *        Pointer-comparison may be used to detect changes from
 *        previous operations.
 * @param tx_bufs Buffer array where data to be sent originates from.
 *
 * @retval 0 If successful.
 * @retval -errno Negative errno code on failure.
 */
spi_write(spi, spi_cfg, &tx);

5.5 读操作¶

实现从slave读取数据

struct spi_buf bufs[] = {
    {
        .buf = data,
        .len = len
    },
};
struct spi_buf_set rx = {
    .buffers = bufs,
    .count = 1
};

/**
 * @brief Read the specified amount of data from the SPI driver.
 *
 * @note This function is synchronous.
 *
 * @note This function is an helper function calling spi_transceive.
 *
 * @param dev Pointer to the device structure for the driver instance
 * @param config Pointer to a valid spi_config structure instance.
 *        Pointer-comparison may be used to detect changes from
 *        previous operations.
 * @param rx_bufs Buffer array where data to be read will be written to.
 *
 * @retval 0 If successful.
 * @retval -errno Negative errno code on failure.
 */
spi_read(spi, spi_cfg, &rx);

5.6 读写操作¶

实现向slave发送数据的同时接收来自slave的数据

struct spi_buf bufs_tx[] = {
		{
				.buf = data,
				.len = len
		},
};

struct spi_buf bufs_rx[] = {
		{
				.buf = data,
				.len = len
		},
};

struct spi_buf_set tx = {
		.buffers = bufs_tx,
		.count = 1
};

struct spi_buf_set rx = {
		.buffers = bufs_rx,
		.count = 1
};

/**
 * @brief Read/write the specified amount of data from the SPI driver.
 *
 * @note This function is synchronous.
 *
 * @param dev Pointer to the device structure for the driver instance
 * @param config Pointer to a valid spi_config structure instance.
 *        Pointer-comparison may be used to detect changes from
 *        previous operations.
 * @param tx_bufs Buffer array where data to be sent originates from,
 *        or NULL if none.
 * @param rx_bufs Buffer array where data to be read will be written to,
 *        or NULL if none.
 *
 * @retval frames Positive number of frames received in slave mode.
 * @retval 0 If successful in master mode.
 * @retval -errno Negative errno code on failure.
 */
spi_transceive(spi, spi_cfg, &tx, &rx);

6 RAM/Flash资源使用情况¶

Memory region         Used Size  Region Size  %age Used
FLASH:       22996 B      1020 KB      2.20%
SRAM:        4808 B        64 KB      7.34%
IDT_LIST:          0 GB         2 KB      0.00%

引脚	功能
P02	CS
P03	SCK
P30	MOSI
P31	MISO