Atmel Xplained Pro Evaluation Kit for the ATSAMD21J18A Microcontroller ATSAMD21-XPRO ATSAMD21-XPRO Data Sheet
Product codes
ATSAMD21-XPRO
886
Atmel | SMART SAM D21 [DATASHEET]
Atmel-42181C–SAM-D21_Datasheet–07/2014
33.9.1 Control A
Name:
CTRLA
Offset:
0x00
Reset:
0x00
Property:
Write-Protected, Write-Synchronized
z
Bit 7 – LPMUX: Low-Power Mux
0: The analog input muxes have low resistance, but consume more power at lower voltages (e.g., are driven by the
voltage doubler).
1: The analog input muxes have high resistance, but consume less power at lower voltages (e.g., the voltage dou-
bler is disabled).
This bit is not synchronized
0: The analog input muxes have low resistance, but consume more power at lower voltages (e.g., are driven by the
voltage doubler).
1: The analog input muxes have high resistance, but consume less power at lower voltages (e.g., the voltage dou-
bler is disabled).
This bit is not synchronized
z
Bits 6:3 – 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.
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
Bit 2 – RUNSTDBY: Run in Standby
This bit controls the behavior of the comparators during standby sleep mode.
0: The comparator pair is disabled during sleep.
1: The comparator pair continues to operate during sleep.
This bit is not synchronized
This bit controls the behavior of the comparators during standby sleep mode.
0: The comparator pair is disabled during sleep.
1: The comparator pair continues to operate during sleep.
This bit is not synchronized
z
Bit 1 – ENABLE: Enable
0: The AC is disabled.
1: The AC is enabled. Each comparator must also be enabled individually by the Enable bit in the Comparator
Control register (COMPCTRLn.ENABLE).
Due to synchronization, there is delay from updating the register until the peripheral is enabled/disabled. The value
written to CTRL.ENABLE will read back immediately after being written. STATUS.SYNCBUSY is set. STA-
TUS.SYNCBUSY is cleared when the peripheral is enabled/disabled.
0: The AC is disabled.
1: The AC is enabled. Each comparator must also be enabled individually by the Enable bit in the Comparator
Control register (COMPCTRLn.ENABLE).
Due to synchronization, there is delay from updating the register until the peripheral is enabled/disabled. The value
written to CTRL.ENABLE will read back immediately after being written. STATUS.SYNCBUSY is set. STA-
TUS.SYNCBUSY is cleared when the peripheral is enabled/disabled.
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 in the AC to their initial state, and the AC 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.
Due to synchronization, there is a delay from writing CTRLA.SWRST until the reset is complete. CTRLA.SWRST
and STATUS.SYNCBUSY will both be cleared when the reset is complete.
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 in the AC to their initial state, and the AC 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.
Due to synchronization, there is a delay from writing CTRLA.SWRST until the reset is complete. CTRLA.SWRST
and STATUS.SYNCBUSY will both be cleared when the reset is complete.
Bit
7
6
5
4
3
2
1
0
LPMUX
RUNSTDBY
ENABLE
SWRST
Access
R/W
R
R
R
R
R/W
R/W
W
Reset
0
0
0
0
0
0
0
0