The problem about RX72M's EtherCAT & SPI

Hello,

     

Using the RX72M chip, EtherCAT Slave is configured and enabled, and SCI8 is configured as SPI in Slave mode. SPI is used to communicate with another DSP board,
After the EtherCAT Slave enters the OP state, the SPI data transmission begins to be unstable. Even if you use SPI to send fixed data (such as 0x37) and use an oscilloscope to observe the 4 pins of SPI, the SS, CLK, and MOSI pins signal is normal, but the MISO pin data is always low, that is, the transmitted data is 0. After EtherCAT Slave is removed from the OP state, the data of each pin of the SPI returns to normal.

Is there a conflict between the RX72M's EtherCAT Slave module and the SPI module? Is there a solution?