I intend to use SPI over USART to drive the BiSS protocol of a sensor.
I configured USART as SPI master with 8 bit, CPHA=1 and CPOL=1. When sending data I check for TXRDY (not TXEMPTY). What I expect is a contigous clock with at contigous data stream when sending my bytes.
But no matter which USART clock I try I always get a gap of 3.5 clock cycles between the 8-bit-clock-sequences. This causes the BiSS protocol to fail.
I need help to figure out how I can get rid of that clock gap.