Схемы, платы, компоненты

Ничего удивительного - это штатная фича, описанная в ДШ The AD7791 can be operated with CS being used as a frame synchronization signal. This scheme is useful for DSP interfaces. In this case, the first bit (MSB) is effectively clocked out by CS since CS would normally occur after the falling edge of SCLK in DSPs. The SCLK can continue to run between data transfers, provided the timing numbers are obeyed. И еще - it is recommended that SCLK idles high between data transfers.