APBA Mask
| PAC_ | PAC APB Clock Enable |
| PM_ | PM APB Clock Enable |
| MCLK_ | MCLK APB Clock Enable |
| RSTC_ | RSTC APB Clock Enable |
| OSCCTRL_ | OSCCTRL APB Clock Enable |
| OSC32KCTRL_ | OSC32KCTRL APB Clock Enable |
| SUPC_ | SUPC APB Clock Enable |
| GCLK_ | GCLK APB Clock Enable |
| WDT_ | WDT APB Clock Enable |
| RTC_ | RTC APB Clock Enable |
| EIC_ | EIC APB Clock Enable |
| FREQM_ | FREQM APB Clock Enable |
| SERCOM0_ | SERCOM0 APB Clock Enable |
| SERCOM1_ | SERCOM1 APB Clock Enable |
| TC0_ | TC0 APB Clock Enable |
| TC1_ | TC1 APB Clock Enable |