23.9.2 Control B in Clock/Calendar mode (CTRLA.MODE=2)

Name: CTRLB
Offset: 0x2
Reset: 0x0000
Property: PAC Write-Protection, Enable-Protected

Bit 15141312111098 
  ACTF[2:0] DEBF[2:0] 
Access R/WR/WR/WR/WR/WR/W 
Reset 000000 
Bit 76543210 
 DMAENRTCOUTDEBASYNC   GP2ENGP0EN 
Access R/WR/WR/WR/WR/W 
Reset 00000 

Bits 14:12 – ACTF[2:0] Active Layer Frequency

These bits define the prescaling factor for the RTC clock output (OUT) used during active layer protection in terms of the CLK_RTC.
ValueNameDescription
0x0 DIV2 CLK_RTC_OUT = CLK_RTC / 2
0x1 DIV4 CLK_RTC_OUT = CLK_RTC / 4
0x2 DIV8 CLK_RTC_OUT = CLK_RTC / 8
0x3 DIV16 CLK_RTC_OUT = CLK_RTC / 16
0x4 DIV32 CLK_RTC_OUT = CLK_RTC / 32
0x5 DIV64 CLK_RTC_OUT = CLK_RTC / 64
0x6 DIV128 CLK_RTC_OUT = CLK_RTC / 128
0x7 DIV256 CLK_RTC_OUT = CLK_RTC / 256

Bits 10:8 – DEBF[2:0] Debounce Frequency

These bits define the prescaling factor for the input debouncers in terms of the CLK_RTC.
ValueNameDescription
0x0 DIV2 CLK_RTC_DEB = CLK_RTC / 2
0x1 DIV4 CLK_RTC_DEB = CLK_RTC / 4
0x2 DIV8 CLK_RTC_DEB = CLK_RTC / 8
0x3 DIV16 CLK_RTC_DEB = CLK_RTC / 16
0x4 DIV32 CLK_RTC_DEB = CLK_RTC / 32
0x5 DIV64 CLK_RTC_DEB = CLK_RTC / 64
0x6 DIV128 CLK_RTC_DEB = CLK_RTC / 128
0x7 DIV256 CLK_RTC_DEB = CLK_RTC / 256

Bit 7 – DMAEN DMA Enable

The RTC can trigger a DMA request when the timestamp is ready in the TIMESTAMP register.
ValueDescription
0 Tamper DMA request is disabled. Reading TIMESTAMP has no effect on INTFLAG.TAMPER.
1 Tamper DMA request is enabled. Reading TIMESTAMP will clear INTFLAG.TAMPER.

Bit 6 – RTCOUT RTC Out Enable

ValueDescription
0 The RTC active layer output is disabled.
1 The RTC active layer output is enabled.

Bit 5 – DEBASYNC Debouncer Asynchronous Enable

ValueDescription
0 The tamper input debouncers operate synchronously.
1 The tamper input debouncers operate asynchronously.

Bit 1 – GP2EN General Purpose 2 Enable

ValueDescription
0 COMP1 compare function enabled. GP2/GP3 disabled.
1 COMP1 compare function disabled. GP2/GP3 enabled.

Bit 0 – GP0EN General Purpose 0 Enable

ValueDescription
0 COMP0 compare function enabled. GP0 disabled.
1 COMP0 compare function disabled. GP0 enabled.