pcf8563 NXP Semiconductors, pcf8563 Datasheet - Page 9

• Manufacturer Part Number: pcf8563
• Description: Real-time Clock/calendar
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCF8563_5
Product data sheet
7.6.4 Alarm registers
Table 14.
Table 15.
When one or more of these registers are loaded with a valid minute, hour, day or weekday
and its corresponding bit Alarm Enable (AE) is logic 0, then that information will be
compared with the current minute, hour, day and weekday. When all enabled comparisons
first match, the Alarm Flag (AF) is set. AF will remain set until cleared by software.
Once AF has been cleared it will only be set again when the time increments to match the
alarm condition once more. Alarm registers which have their bit AE at logic 1 will be
ignored.
Table 16.
Table 17.
Table 18.
Month
July
August
September
October
November
December
Bit
7 to 0
Bit
7
6 to 0
Bit
7
5 to 0
Bit
7
5 to 0
Symbol
YEARS
Symbol
AE
ALARM
_MINUTES
Symbol
AE
ALARM_
HOURS
Symbol
AE
ALARM_
DAYS
Month assignments
Years (address 08h) bits description
Minute alarm (address 09h) bits description
Hour alarm (address 0Ah) bits description
Day alarm (address 0Bh) bits description
Bit 7
C
C
C
C
C
C
Value
00 to 99
Value
0
1
00 to 23
Value
0
1
01 to 31
Value
0
1
00 to 59
Rev. 05 — 17 July 2007
Bit 6
x
x
x
x
x
x
Description
this register holds the current year coded in BCD format
Description
hour alarm is enabled
hour alarm is disabled
this register holds the hour alarm information coded in BCD
format
Description
day alarm is enabled
day alarm is disabled
this register holds the day alarm information coded in BCD format
…continued
Description
minute alarm is enabled
minute alarm is disabled
this register holds the minute alarm information coded in BCD
format
Bit 5
x
x
x
x
x
x
Bit 4
0
0
0
1
1
1
Bit 3
0
1
1
0
0
0
Bit 2
1
0
0
0
0
0
Real time clock/calendar
PCF8563
© NXP B.V. 2007. All rights reserved.
Bit 1
1
0
0
0
0
1
Bit 0
1
0
1
0
1
0
9 of 32