Control A

  0x00 8 - 0x00    

Control A

Bit  7 6 5 4 3 2 1 0  
Access  R/W R/W R/W R/W R/W R/W   R/W  
Reset  0 0 0 0 0 0   0  

Bit 7 – RUNSTDBY: Run in Standby

Run in Standby

0 RTC disabled in Standby sleep mode
1 RTC enabled in Standby sleep mode

Bits 6:3 – PRESCALER[3:0]: Prescaler


These bits define the prescaling of the CLK_RTC clock signal. Due to synchronization between the RTC clock and the peripheral clock, there is a latency of two RTC clock cycles from updating the register until this has an effect. Application software needs to check that the CTRLABUSY flag in the RTC.STATUS register is cleared before writing to this register.

0x0 DIV1 RTC clock/1 (no prescaling)
0x1 DIV2 RTC clock/2
0x2 DIV4 RTC clock/4
0x3 DIV8 RTC clock/8
0x4 DIV16 RTC clock/16
0x5 DIV32 RTC clock/32
0x6 DIV64 RTC clock/64
0x7 DIV128 RTC clock/128
0x8 DIV256 RTC clock/256
0x9 DIV512 RTC clock/512
0xA DIV1024 RTC clock/1024
0xB DIV2048 RTC clock/2048
0xC DIV4096 RTC clock/4096
0xD DIV8192 RTC clock/8192
0xE DIV16384 RTC clock/16384
0xF DIV32768 RTC clock/32768

Bit 2 – CORREN: Frequency Correction Enable

Frequency Correction Enable

0 Frequency correction is disabled
1 Frequency correction is enabled

Bit 0 – RTCEN: RTC Peripheral Enable

RTC Peripheral Enable

0 RTC peripheral is disabled
1 RTC peripheral is enabled