RL78/F13 CAN and CSI10 not working together

RL78/F13 ...  BME controller


I am using CSI10 for SPi (port Pins 74-P77)  and CAN on port Pins P72 and P73.
I have set PIOR registers as required. 
PIOR4 = 0x4CU;   PIOR5 = 0x01U;    PIOR6 = 0x40U;
My CAN is working when SAU1EN = 0. but when SAU1EN = 1, CAN does not work.( but CSI10 SPI works correctly).
I have checked port pin settings and PIOR registers.
Can you help resolve the issue ???