SWCU193A April 2023 – August 2024 CC2340R2 , CC2340R5 , CC2340R5-Q1
The SPI includes a programmable bit rate clock divider and prescaler to generate the serial output clock.
The serial bit rate is derived by dividing down the input clock, CLKSVT (48MHz).
First, the clock is divided by a prescaler with a value from 1 to 8, which is programmed in the SPI.CLKCFG0[2:0] PRESC field (a value of 0x1 means that the clock is divided by 2). The clock is further divided by a value from 2 to 2048, which is 2×(1 + SCR), where SCR is the value programmed in the SPI.CLKCFG1[9:0] SCR field.
Equation 9 defines the frequency of the output clock SCLK.
The maximum SPI frequency supported with controller and peripheral modes depends on the device clock option and IO option. Please refer to specific device data sheet specification for more information.