Datasheet

16 - REAL TIME CLOCK ST10F269
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16.1.5 - RTCAH & RTCAL: RTC ALARM Registers
When the programmable counters reach the 32-bit value stored into RTCAH & RTCAL registers, an alarm
is triggered and the interrupt request RTAIR is generated. Those registers are not protected.
RTCAL (EC12h) XBUS Reset Value: XXXXh
RTCAH (EC14h) XBUS Reset Value: XXXXh
Note: Those registers are not reset
16.2 - Programming the RTC
RTC interrupt request signals are connected to Port2, pad 10 (RTCSI) and pad 11 (RTCAI). An alternate
function Port2 is to generate fast interrupts firq[7:0]. To trigger firq[2] and firq[3] the following configuration
has to be set.
EXICON ESFR controls the external interrupt edge selection, RTC interrupt requests are rising edge
active.
EXICON (F1C0h) ESFR Reset Value: 0000h
Notes: 1. EXI2ES and EXI3ES must be configured as "01b" because RCT interrupt request lines are rising edge active.
2. Alarm interrupt request line (RTCAI) is linked with EXI3ES.
3. Timed interrupt request line (RTCSI) is linked with EXI2ES.
EXISEL ESFR enables the Port2 alternate sources. RTC interrupts are alternate sources 2 and 3.
EXISEL (F1DAh) ESFR Reset Value: 0000h
Notes: 1. Advised configuration.
2. Alarm interrupt request (RTCAI) is linked with EXI3SS.
3. Timed interrupt request (RTCSI) is linked with EXI2SS.
1514131211109876543210
RTCAL
RW
1514131211109876543210
RTCAH
RW
1514131211109876543210
EXI7ES EXI6ES EXI5ES EXI4ES EXI3ES
1 2
EXI2ES
1 3
EXI1ES EXI0ES
RW RW RW RW RW RW RW RW
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EXI7SS EXI6SS EXI5SS EXI4SS EXI3SS
2
EXI2SS
3
EXI1SS EXI0SS
RW RW RW RW RW RW RW RW
EXIxSS External Interrupt x Source Selection (x=7...0)
‘00’: Input from associated Port 2 pin.
‘01’: Input from “alternate source”.
1
‘10’: Input from Port 2 pin ORed with “alternate source”.
1
‘11’: Input from Port 2 pin ANDed with “alternate source”.