SH7713 datasheet(567/904 Pages) RENESAS

Part #	SH7713

Description	Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series

PDF	904 Pages

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Manufacturer	RENESAS [Renesas Technology Corp]

Direct Link	http://www.renesas.com

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Section 15 Realtime Clock (RTC)

Rev.1.50 Aug. 30, 2006 Page 527 of 860

REJ09B0288-0150

15.4.4

Alarm Function

Figure 15.4 shows how to use the alarm function.

Alarms can be generated using seconds, minutes, hours, day of the week, date, month, year, or any

combination of these. Set the ENB bit or YAEN bit in the register on which the alarm is placed to

1, and then set the alarm time in the lower bits. Clear the ENB bit in the register on which the

alarm is not placed to 0.

When the clock and alarm times match, 1 is set in the AF bit in RCR1. Alarm detection can be

checked by reading this bit, but normally it is done by interrupt. If 1 is set in the AIE bit in RCR1,

an interrupt is generated when an alarm occurs.

Disable interrupt to prevent errorneous

interruption.(AIE bit in RCR1 is cleared)

Then write 1.

Clock running

Set alarm time

Set whether to use

alarm interrupt

Always clear, since the flag may have been

set while the alarm time was being set.

(Write 0 to AF of RCR1 to clear it. )

Clear alarm flag

Monitor alarm time

(wait for interrupt or

check alarm flag)

Figure 15.4 Using Alarm Function

SH7713 Datasheet(PDF) 567 Page - Renesas Technology Corp