PCF8563 데이터 시트보기 (PDF) - Philips Electronics
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PCF8563 Datasheet PDF : 30 Pages
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Philips Semiconductors
PCF8563
Real-time clock/calendar
8.6.2 Control/Status 2 register
Table 7:
Bit
7 to 5
4
3
2
1
0
Description of Control/Status 2 register bits description (address 01H)
Symbol Description
0
By default set to logic 0.
TI/TP TI/TP = 0: INT is active when TF is active (subject to the status of TIE).
TI/TP = 1: INT pulses active according to Table 8 (subject to the status
of TIE). Note that if AF and AIE are active then INT will be permanently
active.
AF
When an alarm occurs, AF is set to logic 1. Similarly, at the end of a
TF
timer countdown, TF is set to logic 1. These bits maintain their value
until overwritten by software. If both timer and alarm interrupts are
required in the application, the source of the interrupt can be
determined by reading these bits. To prevent one flag being
overwritten while clearing another, a logic AND is performed during a
write access. See Table 9 for the value descriptions of bits AF and TF.
AIE
Bits AIE and TIE activate or deactivate the generation of an interrupt
TIE
when AF or TF is asserted, respectively. The interrupt is the logical OR
of these two conditions when both AIE and TIE are set.
AIE = 0: alarm interrupt disabled; AIE = 1: alarm interrupt enabled.
TIE = 0: timer interrupt disabled; TIE = 1: timer interrupt enabled.
Table 8: INT operation (bit TI/TP = 1)
Source clock (Hz)
INT [1] period (s)
n [2] = 1
4 096
64
1⁄8192
1⁄128
1
1⁄64
1⁄60
1⁄64
[1] TF and INT become active simultaneously.
[2] n = loaded countdown timer value. Timer stopped when n = 0.
n>1
1⁄4096
1⁄64
1⁄64
1⁄64
Table 9: Value descriptions for bits AF and TF
R/W Bit: AF
Bit: TF
Value Description
Value Description
Read 0 alarm flag inactive
0 timer flag inactive
1 alarm flag active
1 timer flag active
Write 0 alarm flag is cleared
0 timer flag is cleared
1 alarm flag remains unchanged 1 timer flag remains unchanged
9397 750 04855
Product specification
16 April 1999
© Philips Electronics N.V. 1999. All rights reserved.
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