CCS/AM5718: McSPI maximum data size

Part Number: AM5718

Tool/software: Code Composer Studio

Hii,

What is the maximum data size that we can transfer using MCSPI in AM5718 processor ?

We are accessing ARINC429 through MCSPI1(drivers). In which we need to access 5bytes(1byte opcode + 4 bytes data)  to read a FIFO.

We need CS to be active for 5bytes continuously.

How can I do this ?

NOTE : We have tried with 8bit data size , but it does not work.

Thanks and Regards

Arpita Jena