Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Atmel/AT91SAM9M11/PMC/CKGR_PLLAR#0x0
PLLA Register
Divider A
PLLA Counter
PLLA Clock Frequency Range
PLLA Multiplier
https://github.com/cmsis-svd/cmsis-svd-data