Calculate the Baudrate in SPI?

[Muzahir Hussain]

Posted on February 10, 2018 at 19:56

How do I calculate the SPI baudrate in nucleo STM32F103RB?

In reference manual it says, 

Bits 5:3 BR[2:0]: Baud rate control

000: fPCLK/2001: fPCLK/4010: fPCLK/8011: fPCLK/16100: fPCLK/32101: fPCLK/64110: fPCLK/128111: fPCLK/256

What does it mean??

#stm32f103rb #stm32-f3 #spi-communication

[Tesla DeLorean]

Posted on February 10, 2018 at 20:19

Take the APB clock that the SPI peripheral is attached too and divide it down.

ie

rate = HAL_RCC_GetPCLK2Freq() / 8;

For a 72 MHz bus this would be a 9 MHz SPI1