Datasheet

45.8.1 Control A
Name: CTRLA
Offset: 0x00
Reset: 0x0000
Property: Enable-Protected, PAC Write-Protection, Write-Synchronized
Bit 15 14 13 12 11 10 9 8
R2R PRESCALER[2:0]
Access
R/W R/W R/W R/W
Reset 0 0 0 0
Bit 7 6 5 4 3 2 1 0
ONDEMAND RUNSTDBY SLAVEEN DUALSEL[1:0] ENABLE SWRST
Access
R/W R/W R/W R/W R/W R/W R/W
Reset 0 0 0 0 0 0 0
Bit 15 – R2R Rail to Rail Operation Enable
Value Description
0
Rail-to-Rail operation disable
1
Rail-to-Rail operation enable. The R2R bit must be set to ‘1’ only in differential mode.
Bits 10:8 – PRESCALER[2:0] Prescaler Configuration
This field defines the ADC clock relative to the peripheral clock according Table below. This field is not
synchronized. For the slave ADC, these bits have no effect when the SLAVEEN bit is set
(CTRLA.SLAVEEN= 1).
Value Name Description
0x0
DIV2 Peripheral clock divided by 2
0x1
DIV4 Peripheral clock divided by 4
0x2
DIV8 Peripheral clock divided by 8
0x3
DIV16 Peripheral clock divided by 16
0x4
DIV32 Peripheral clock divided by 32
0x5
DIV64 Peripheral clock divided by 64
0x6
DIV128 Peripheral clock divided by 128
0x7
DIV256 Peripheral clock divided by 256
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.
Note: For the slave ADC, this bit has no effect when the SLAVEEN bit is set (CTRLA.SLAVEEN= 1).
ONDEMAND bit from master ADC instance will control the On Demand operation mode.
SAM D5x/E5x Family Data Sheet
ADC – Analog-to-Digital Converter
© 2019 Microchip Technology Inc.
Datasheet
DS60001507E-page 1608