SPI Clock Selection

The clock source for SPI Host modes is selected by the SPIxCLK register.

The SPIxBAUD register allows for dividing this clock. The frequency of the SCK output is defined by the following equation:

Figure 1. SCK Output Frequency

FBAUD=FCSEL2×(BAUD+1)

where FBAUD is the baud rate frequency output on the SCK pin, FCSEL is the frequency of the input clock selected by the SPIxCLK register, and BAUD is the value contained in the SPIxBAUD register.