Interfacing to High Speed ADCs via SPI:This application note describes how to use the SPI port on The SPI port consists of three pins: the serial clock pin (SCLK), Analog Devices, Inc., high speed converters. In addition, this the serial data input/output pin (SDIO), and the chip select bar application note defines the electrical, timing, and procedural pin (CSB). Optionally, some chips may implement a serial data requirements for interfacing to these devices. The implementa-out pin (SDO), which is referred to as 3-wire mode. To minimize tion is compatible with industry-standard SPI ports and pin count, most chips omit this pin. However, if it is included, it is employs, at minimum, a 2-wire mode and optional chip select. used only for reading data from the device.