20.8.1 Control A

Name: CTRLA
Offset: 0x00
Reset: 0x00
Property: PAC Write-Protection

Bit 76543210 
       ENABLESWRST 
Access R/WR/W 
Reset 00 

Bit 1 – ENABLE Enable

Due to synchronization there is delay from writing CTRLA.ENABLE until the peripheral is enabled or disabled. The value written to CTRLA.ENABLE will read back immediately and the ENABLE bit in the Synchronization Busy register (SYNCBUSY.ENABLE) will be set. SYNCBUSY.ENABLE will be cleared when the operation is complete.

ValueDescription
0 The peripheral is disabled.
1 The peripheral is enabled.

Bit 0 – SWRST Software Reset

Writing a '0' to this bit has no effect.

Writing a '1' to this bit resets all registers in the FREQM to their initial state, and the FREQM will be disabled. Writing a '1' to this bit will always take precedence, meaning that all other writes in the same write-operation will be discarded.

Note:
  1. When the CTRLA.SWRST is written, the user must poll the SYNCBUSY.SWRST bit to know when the reset operation is complete.
  2. During a SWRST, access to registers/bits without SWRST are disallowed until the SYNCBUSY.SWRST is cleared by hardware.
ValueDescription
0 There is no ongoing Reset operation.
1 The Reset operation is ongoing.