RM0017 Datasheet, PDF (252/904 Pages) STMicroelectronics – The SPC560Bx and SPC560Cx is a new family

RM0017
Real Time Clock / Autonomous Periodic Interrupt (RTC/API)
Field
ROVREN
RTCVAL
APIEN
APIIE
CLKSEL
DIV512EN
DIV32EN
APIVAL
Table 109. RTCC field descriptions (continued)
Description
Counter Roll Over Wakeup/Interrupt Enable
The ROVREN bit enables wakeup and interrupt requests when the RTC has rolled over from
0xFFFF_FFFF to 0x0000_0000. The RTCIE bit must also be set in order to generate an interrupt
from a counter rollover.
1 RTC rollover wakeup/interrupt enabled
0 RTC rollover wakeup/interrupt disabled
RTC Compare Value
The RTCVAL bits are compared to bits 10:21 of the RTC counter and if match sets RTCF. RTCVAL
can be updated when the counter is running.
Note: RTCVAL = 0 does not generate an interrupt.
Autonomous Periodic Interrupt Enable
The APIEN bit enables the autonomous periodic interrupt function.
1 API enabled
0 API disabled
API Interrupt Enable
The APIIE bit enables interrupts requests to the system if APIF is asserted.
1 API interrupts enabled
0 API interrupts disabled
Clock Select
This field selects the clock source for the RTC. CLKSEL may only be updated when CNTEN is 0.
The user should ensure that oscillator is enabled before selecting it as a clock source for RTC.
00 SXOSC
01 SIRC
10 FIRC
11 Reserved
Divide by 512 enable
The DIV512EN bit enables the 512 clock divider. DIV512EN may only be updated when CNTEN is
0.
0 Divide by 512 is disabled.
1 Divide by 512 is enabled.
Divide by 32 enable
The DIV32EN bit enables the 32 clock divider. DIV32EN may only be updated when CNTEN is 0.
0 Divide by 32 is disabled.
1 Divide by 32 is enabled.
API Compare Value
The APIVAL field is compared with bits 22:31 of the RTC counter and if match asserts an
interrupt/wakeup request. APIVAL may only be updated when APIEN is 0 or API function is
undefined.
Note: API functionality starts only when APIVAL is non zero. The first API interrupt takes two more
cycles because of synchronization of APIVAL to the RTC clock. After that interrupts are
periodic in nature. The minimum supported value of APIVAL is 4.
Doc ID 14629 Rev 8
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