Control A in COUNT16 mode (CTRLA.MODE=1)
Bit15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 |
COUNTSYNC | PRESCALER[3:0] | ||||||
AccessR/W | R/W | R/W | R/W | R/W | |||
Reset0 | 0 | 0 | 0 | 0 | |||
Bit7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
MODE[1:0] | ENABLE | SWRST | |||||
Access | R/W | R/W | R/W | R/W | |||
Reset | 0 | 0 | 0 | 0 |
COUNT Read Synchronization Enable
This bit is not enable-protected.
Value | Description |
---|---|
0 | COUNT read synchronization is disabled |
1 | COUNT read synchronization is enabled |
Prescaler
Value | Name | Description |
---|---|---|
0x0 | OFF | CLK_RTC_CNT = GCLK_RTC/1 |
0x1 | DIV1 | CLK_RTC_CNT = GCLK_RTC/1 |
0x2 | DIV2 | CLK_RTC_CNT = GCLK_RTC/2 |
0x3 | DIV4 | CLK_RTC_CNT = GCLK_RTC/4 |
0x4 | DIV8 | CLK_RTC_CNT = GCLK_RTC/8 |
0x5 | DIV16 | CLK_RTC_CNT = GCLK_RTC/16 |
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 |
Operating Mode
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 |
Enable
Value | Description |
---|---|
0 | The peripheral is disabled |
1 | The peripheral is enabled |
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.
Value | Description |
---|---|
0 | There is not reset operation ongoing |
1 | The reset operation is ongoing |