Cyclone® V Hard Processor System Technical Reference Manual

ID 683126
Date 8/28/2023
Public
Document Table of Contents

20.4.3.3. Receive Only

When TMOD = 2, the transmit data are invalid. In the case of the SPI slave, the transmit FIFO buffer is never popped in Receive Only mode. The txd output remains at a constant logic level during the transmission. The data transfer occurs as normal according to the selected frame format (serial protocol). The receive data from the target device is moved from the receive shift register into the receive FIFO buffer at the end of each data frame. You should mask interrupts originating from the transmit logic when this mode is entered. †