PCF8563BS NXP [NXP Semiconductors], PCF8563BS Datasheet - Page 10

• Manufacturer Part Number: PCF8563BS
• Description: Real-time clock/calendar
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
PCF8563_6
Product data sheet
7.6.5 Clock output control register
7.6.6 Countdown timer
Table 18.
Table 19.
Table 20.
Table 21.
The timer register is an 8-bit binary countdown timer. It is enabled and disabled via the
timer control register bit TE. The source clock for the timer is also selected by the timer
control register. Other timer properties such as interrupt generation are controlled via
control_status
For accurate read back of the countdown value, the I
operating at a frequency of at least twice the selected timer clock.
Bit
7
6
5 to 0
Bit
7
6 to 3
2 to 0
Bit
7
6 to 2
1 to 0
FD1
0
0
1
1
Symbol
AE
x
ALARM_DAYS[5:0]
Symbol
AE
x
ALARM_
WEEKDAYS[2:0]
Symbol
FE
x
FD[1:0]
Day_alarm - Day alarm register (address 0Bh) bit description
Weekday_alarm - Weekday alarm register (address 0Ch) bit description
CLKOUT_control - CLKOUT control register (address 0Dh) bit description
FD1 and FD0: CLKOUT frequency selection
_
2 register.
Rev. 06 — 21 February 2008
Value
0
1
see
FD0
0
1
0
1
Table 21
Value
0
1
01 to 31
Value
0
1
0 to 6
Description
day alarm is enabled
day alarm is disabled
not relevant
the day alarm information, coded in BCD format
Description
weekday alarm is enabled
weekday alarm is disabled
not relevant
the weekday alarm information, coded in BCD
format
Description
the CLKOUT output is inhibited and set to
high-impedance
the CLKOUT output is activated
not relevant
these bits control the frequency output at
pin CLKOUT
CLKOUT frequency
32.768 kHz
1024 Hz
32 Hz
1 Hz
2
C-bus clock (SCL) must be
Real-time clock/calendar
PCF8563
© NXP B.V. 2008. All rights reserved.
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