# SPI Frequency Set the SPI clock frequency. ```sig pins.spiFrequency(1000000); ``` ## Parameters * **frequency**: a [number](/types/number) to set as the frequency for SPI bus clock. This value is the number of clock changes per second (Hz). ## Example Read the value of the _WHOAMI_ register from the device connected to the SPI bus. The chip select line is connected to pin **0** and the SPI signals use pins **13**, **14**, and **15**. ```blocks pins.digitalWritePin(DigitalPin.P0, 1); pins.spiPins(DigitalPin.P15, DigitalPin.P14, DigitalPin.P13); pins.spiFormat(8, 3); pins.spiFrequency(1000000); pins.digitalWritePin(DigitalPin.P0, 0); let command = pins.spiWrite(143); let whoami = pins.spiWrite(0); pins.digitalWritePin(DigitalPin.P0, 1); basic.showNumber(whoami); serial.writeLine("WHOAMI register value: " + whoami) ``` ## See also [SPI](https://developer.mbed.org/handbook/SPI)