In normal work, if you use the MSP430 as the master chip, you often encounter the need to write SPI or I2C drivers to read and control peripherals (such as LCD screens, some sensors). In order to reduce repetitive work, this article summarizes the detailed steps of SPI driver writing (using the MSP430FR6989 to drive the integrated analog front end AFE4400) with specific examples: Microcontroller SPI pin settings SPI read and write timing settings Register write Write last Microcontroller SPI pin settings The general SPI has 3 lines and 4 lines, the difference lies in whether the chip select terminal - STE pin, 4 pin function description: UCxS0MI: Main mode data input, data output from slave mode; UCxSIMO: main mode data output, data input from the slave mode; UCxCLK: USCI SPI clock; UCxSTE: Enabler of the USCI SPI; Pin setting code: SPI read and write timing settings According to the data sheet, the reading and writing of the module's SPI read and write timing is a key step for success! ! ! The following is the AFE4400 SPI read and write timing diagram: When reading data: Pull down the STE, first send a byte of register address to the AFE4400, wait for a while, the AFE4400 will return the address of the data to the microcontroller, send a byte by byte, a total of 3 bytes 24 bits data. (SCM needs to send three times at a time) When writing data: Pull down the STE, first send the register address you want to write, and then send 3 bytes of 24-bit data in order, you can change the corresponding register data in AFE4400. (SCM needs to send three times at a time) SPI reads the code of the AFE4400 register value: The SPI writes data to the code in the AFE4400 register: Register write After completing the above two steps, we can use the AFE4400 for us and listen to us! By reading the register function manual and writing the corresponding value to configure the function of the AFE4400, we can achieve the functions we want. AFE4400 some registers: Conecting Terminals Without Screws Conecting Terminals Without Screws,Cold Pressing Terminals,Low Pressure Cold Shrinkage Terminal,Cold Shrinkage Cable Terminals Taixing Longyi Terminals Co.,Ltd. , https://www.longyiterminals.com
