Datasheet

Table Of Contents
Value Name Description
0x6
DIV32 CLK_RTC_CNT = GCLK_RTC/32
0x7
DIV64 CLK_RTC_CNT = GCLK_RTC/64
0x8
DIV128 CLK_RTC_CNT = GCLK_RTC/128
0x9
DIV256 CLK_RTC_CNT = GCLK_RTC/256
0xA
DIV512 CLK_RTC_CNT = GCLK_RTC/512
0xB
DIV1024 CLK_RTC_CNT = GCLK_RTC/1024
0xC-0xF
- Reserved
Bit 7 – MATCHCLR Clear on Match
This bit is valid only in Mode 0 (COUNT32) and Mode 2 (CLOCK). This bit can be written only when the
peripheral is disabled. This bit is not synchronized.
Value Description
0
The counter is not cleared on a Compare/Alarm 0 match
1
The counter is cleared on a Compare/Alarm 0 match
Bit 6 – CLKREP Clock Representation
This bit is valid only in Mode 2 and determines how the hours are represented in the Clock Value
(CLOCK) register. This bit can be written only when the peripheral is disabled. This bit is not
synchronized.
Value Description
0
24 Hour
1
12 Hour (AM/PM)
Bits 3:2 – MODE[1:0] Operating Mode
This field defines the operating mode of the RTC. This bit is not synchronized.
Value Name Description
0x0
COUNT32 Mode 0: 32-bit counter
0x1
COUNT16 Mode 1: 16-bit counter
0x2
CLOCK Mode 2: Clock/calendar
0x3
- Reserved
Bit 1 – ENABLE Enable
Due to synchronization there is delay from writing CTRLA.ENABLE until the peripheral is enabled/
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.
Value Description
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 RTC, except DBGCTRL, to their initial state, and the RTC
will be disabled.
Writing a '1' to CTRLA.SWRST will always take precedence, meaning that all other writes in the same
write-operation will be discarded.
Due to synchronization there is a delay from writing CTRLA.SWRST until the reset is complete.
CTRLA.SWRST will be cleared when the reset is complete.
SAM D5x/E5x Family Data Sheet
RTC – Real-Time Counter
© 2019 Microchip Technology Inc.
Datasheet
DS60001507E-page 352