Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Renesas Electronics/R7FA6M3AH/BUS/SDADR#0x0
MXC=00
SDRAM Address Register
Address Multiplex Select
0 (00): 8-bit shift
1 (01): 9-bit shift
2 (10): 10-bit shift
3 (11): 11-bit shift
https://github.com/cmsis-svd/cmsis-svd-data