41.8.1. Control A
Name:
CTRLA
Offset:
0x00
Reset:
0x00
Property:
PAC Write-Protection, Write-Synchronized
Bit
7
6
5
4
3
2
1
0
ONDEMAND
RUNSTDBY
ENABLE
SWRST
Access
R/W
R/W
R/W
R/W
Reset
0
0
0
0
Bit 7 – ONDEMAND: On Demand Control
The On Demand operation mode allows the ADC to be enabled or disabled, depending on other
peripheral requests.
In On Demand operation mode, i.e., if the ONDEMAND bit has been previously set, the ADC will only be
running when requested by a peripheral. If there is no peripheral requesting the ADC will be in a disable
state.
If On Demand is disabled the ADC will always be running when enabled.
In standby sleep mode, the On Demand operation is still active if the CTRLA.RUNSTDBY bit is '1'. If
CTRLA.RUNSTDBY is '0', the ADC is disabled.
This bit is not synchronized.
Value
Description
0
The ADC is always on , if enabled.
1
The ADC is enabled, when a peripheral is requesting the ADC conversion. The ADC is
disabled if no peripheral is requesting it.
Bit 6 – RUNSTDBY: Run in Standby
This bit controls how the ADC behaves during standby sleep mode.
This bit is not synchronized.
Value
Description
0
The ADC is halted during standby sleep mode.
1
The ADC is not stopped in standby sleep mode. If CTRLA.ONDEMAND=1, the ADC will be
running when a peripheral is requesting it. If CTRLA.ONDEMAND=0, the ADC will always be
running in standby sleep mode.
Bit 1 – ENABLE: Enable
Due to synchronization there is delay from writing CTRLA.ENABLE until the peripheral is enabled/
disabled. The value written to CTRL.ENABLE will read back immediately and the ENABLE bit in the
SYNCBUSY register (SYNCBUSY.ENABLE) will be set. SYNCBUSY.ENABLE will be cleared when the
operation is complete.
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
1003