The TXE8124 devices use a SPI interface to set device configurations, operating parameters and read out diagnostic information. The SPI protocol uses three inputs and one output; serial clock (SCLK), active LOW chip select (CS), serial data in (SDI) and serial data out (SDO). CS must be driven low before clock pulses and data into the device. When CS is high, the device ignores all activity on SCLK and SDI.

The TXE8124 devices support SPI mode 0 (CPOL = 0, CPHA = 0). The clock (SCLK) is low when idle. Data is sampled on the rising edge of SCLK and changed on the falling edge.

Besides SPI bus with independent chip select, daisy chain configuration is also supported in TXE8124. It allows multiple peripherals to be connected in series, with the output of one device feeding into the input of the next. Daisy chain is benefitial to reduce the number of CS lines, as only one is needed for the entire chain. Data is shifted through all devices in the chain during each clock cycle.