Welcome to STM32-BoardCar repository

13. Off-chip Flash (SPI)

Off-chip Flash

Off-chip Flash1、Software-Hardware2、Brief principle2.1、Hardware schematic diagram2.2、Physical connection diagram2.3、Principle of control3、Engineering configuration3.1、Notes3.2、Pin configuration4、Main function4.1、User function4.2、HAL library function parsing5、Experimental phenomenon

This tutorial demonstrates: using SPI (SPI2) to control the external Flash (W25Q64) to read and write data, and print the data through the serial port (USART1)

1、Software-Hardware

STM32F103CubeIDE
STM32 Robot Development board
USART: Chip internal peripheral
Key, external Flash (W25Q64) : onboard
Type-C cable or ST-Link
Download or simulate the program of the development board

2、Brief principle

2.1、Hardware schematic diagram

2.2、Physical connection diagram

2.3、Principle of control

Write, read and erase the data of external flash by key control, and print the data through the serial port.

GPIO reading

By defining different functions for the key, the read and write operation of data in W25Q64 is realized.

KEY（Schematic name）	Control pin	Function
KEY1	PG3	Add 1 to the count
KEY2	PG4	Reading count values
KEY3	PG5	Erasing data

External Flash

W25Q64 divides the capacity of 8M bytes into 128 blocks of 64K bytes each, and each block is further divided into 16 sectors of 4K bytes each. The minimum erasing unit for W25Q64 is one sector, which means that 4K bytes must be erased at a time.

Instruction list（truncated）


Instructions for detailed use of the reference [W25Q64JV_ English Reference Manual]

SPI

Serial Peripheral Interface (SPI) is a high-speed, full-duplex, synchronous serial communication interface, which is often used to transfer data between microcontrollers, sensors and peripheral devices.

SPI pins	Function
MISO	Master device data output line, from the master device to the slave device to send data
MOSI	The master device data input line transfers data from the slave device to the master device
SCLK	Clock signal line for timing control of synchronous data transmission
CS	The slave selection line is used to select a specific slave device to communicate with the master device

SPI transmission mode

Polarity of clock（CPOL）：Controls the idle and active states of the clock signal (0: idle low, 1: idle high)

Phase of clock（CPHA）：Sampling and transmission time of control data (0: sampling along odd hops, 1: sampling along even hops)

Polarity of clock（CPOL）	Phase of clock（CPHA）
0	0	SCL idle state low level; The data is sampled on the rising edge and transmitted on the falling edge
0	1	SCL idle state low level; Data is sampled on the falling edge and data is transmitted on the rising edge
1	0	SCL idle state high level; Data is sampled on the falling edge and data is transmitted on the rising edge
1	1	SCL idle state high level; The data is sampled on the rising edge and transmitted on the falling edge

3、Engineering configuration

Project Configuration: Prompts for configuration options in the STM32CubeIDE project configuration process

3.1、Notes

Omitted project configuration: New project, chip selection, project configuration, SYS for pin configuration, RCC configuration, clock configuration, and project configuration content

The project configuration part, which is not omitted, is the key point to configure in this tutorial.


xxxxxxxxxx
Please refer to [2. Development environment construction and use: STM32CubeIDE installation and use] to understand how to configure the omitted parts of the project.

3.2、Pin configuration

Configure the specified pin function

You can directly select the corresponding pin number in the pin view, and the corresponding option will appear when the mouse is left clicked

42f83437848aad391548eb47dc66a0a6

GPIO

SPI

USART

NVIC
NVIC可修改中断优先级

Generating code

4、Main function

This section mainly introduces the functional code written by users. ** Detailed code can be opened by yourself in the project file we provide, and enter the Bsp folder to view the source code. **

4.1、User function

function：Spi_Flash_ReadID

Function prototypes	u16 Spi_Flash_ReadID(void)
Functional Description	Read the W25Q64 chip ID
Input parameters	None
Return value	ID number

function：Spi_Flash_Erase_Sector

Function prototypes	void Spi_Flash_Erase_Sector(u32 Dst_Addr)
Functional Description	Erases a sector
Input parameters	Sector address
Return value	None

function：Spi_Flash_Write

Function prototypes	void Spi_Flash_Write(u8 *pBuffer, u32 WriteAddr, u16 NumByteToWrite)
Functional Description	Writes data of the specified length starting at the specified address
Input parameters1	Data storage area
Input parameters2	Address to write to
Input parameters3	Number of bytes written
Return value	None

function：Spi_Flash_Read

Function prototypes	void Spi_Flash_Read(u8 *pBuffer, u32 ReadAddr, u16 NumByteToRead)
Functional Description	Reads data of the specified length starting at the specified address
Input parameters1	Data storage area
Input parameters2	Read address
Input parameters3	The number of bytes read
Return value	None

4.2、HAL library function parsing

The HAL library functions that were covered in the previous tutorial will not be covered


xxxxxxxxxx
If you want to find the HAL library and LL library function analysis involved in the entire tutorial, you can view the documents in the folder [8. STM32 Manual: STM32F1_HAL Library and LL Library_User Manual]

function：HAL_SPI_Init

Function prototypes	HAL_StatusTypeDef HAL_SPI_Init(SPI_HandleTypeDef *hspi)
Functional Description	Initialize the SPI parameters
Input parameters	hspi：SPI handle address
Return value	HAL status value：HAL_OK、HAL_ERROR、HAL_BUSY、HAL_TIMEOUT

function：HAL_SPI_MspInit

Function prototypes	void HAL_SPI_MspInit(SPI_HandleTypeDef *hspi)
Functional Description	Initialize the peripheral clock, GPIO, and NVIC of SPI
Input parameters	hspi：SPI handle address
Return value	None

function：HAL_SPI_MspDeInit

Function prototypes	void HAL_SPI_MspDeInit(SPI_HandleTypeDef *hspi)
Functional Description	Uninitialize the SPI peripheral clock, GPIO, and NVIC
Input parameters	hspi：SPI handle address
Return value	None

5、Experimental phenomenon

After downloading the program successfully, press the RESET button of the development board to open the serial debugging assistant to observe the phenomenon


xxxxxxxxxx
For program download, please refer to [2. Development environment construction and use: program download and simulation]

phenomenon：

Press RESET button: the serial debugging assistant will print the detection status of the external Flash chip;

Press KEY1: The serial debugging assistant will add 1 to the count value and write the value to the external Flash chip;

Press KEY2: The serial debugging assistant will output the numerical value stored in the specified sector of the external Flash chip;

Press KEY3: The serial debugging assistant will erase the specified sector data.

I2C Communication (IIC)

On-chip Flash (Flash)