Data Sheet

594
Atmel | SMART SAM D21 [DATASHEET]
Atmel-42181G–SAM-D21_Datasheet–09/2015
28.9.1 Control A
Name: CTRLA
Offset: 0x00
Reset: 0x00
Property: Write-Protected, Write-Synchronized
z Bits 7:6 – Reserved
These bits are unused and reserved for future use. For compatibility with future devices, always write these bits to
zero when this register is written. These bits will always return zero when read.
z Bits 5:4 – SERENx [x=1..0]: Serializer x Enable
0: The Serializer x is disabled.
1: The Serializer x is enabled.
Writing a zero to this bit will disable the Serializer x.
Writing a one to this bit will enable the Serializer x.
z Bits 3:2 – CKENx [x=1..0]: Clock Unit x Enable
0: The Clock Unit x is disabled.
1: The Clock Unit x is enabled.
Writing a zero to this bit will disable the Clock Unit x.
Writing a one to this bit will enable the Clock Unit x.
z Bit 1 – ENABLE: Enable
0: The peripheral is disabled.
1: The peripheral is enabled.
Writing a zero to this bit will disable the module.
Writing a one to this bit will enable the module.
z Bit 0 – SWRST: Software Reset
0: There is no reset operation ongoing.
1: The reset operation is ongoing.
Writing a zero to this bit has no effect.
Writing a one to this bit resets all registers to their initial state, and the peripheral will be disabled.
Writing a one to CTRL.SWRST will always take precedence, meaning that all other writes in the same write-oper-
ation will be discarded.
Bit 76543210
SEREN1 SEREN0 CKEN1 CKEN0 ENABLE SWRST
Access R R R/W R/W R/W R/W R/W R/W
Reset00000000