pcf8564a NXP Semiconductors, pcf8564a Datasheet - Page 20
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pcf8564a
Manufacturer Part Number
pcf8564a
Description
Real Time Clock And Calendar
Manufacturer
NXP Semiconductors
Datasheet
1.PCF8564A.pdf
(44 pages)
Available stocks
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Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
pcf8564aCX9/B/1
Manufacturer:
NXP
Quantity:
20 319
NXP Semiconductors
PCF8564A_1
Product data sheet
Fig 11. POR override sequence
Allow 500 ns between the edges of either signal.
SDA
SCL
8.11.1 Power-On Reset (POR) override
power up
8 ms
Table 27.
[1]
The POR duration is directly related to the crystal oscillator start-up time. Due to the long
start-up times experienced by these types of circuits, a circuit has been implemented to
disable the POR and speed up functional test of the module. The setting of this mode
requires that the I
Figure
Once the override mode has been entered, the chip immediately stops, being reset, and
normal operation may begin, i.e., entry into the EXT_CLK test mode via I
override mode may be cleared by writing logic 0 to TESTC. TESTC must be set to logic 1
before re-entry into the override mode is possible. Setting TESTC to logic 0 during normal
operation has no effect, except to prevent entry into the POR override mode.
Address Register name
00h
01h
02h
03h
04h
05h
06h
07h
08h
09h
0Ah
0Bh
0Ch
0Dh
0Eh
0Fh
Registers marked ‘x’ are undefined at power-on and unchanged by subsequent resets.
11. All timings shown are required minimums.
Control_1
Control_2
Seconds
Minutes
Hours
Days
Weekdays
Months
Years
Minute_alarm
Hour_alarm
Day_alarm
Weekday_alarm
CLKOUT_ctrl
Timer_ctrl
Timer
Register reset values
500 ns
2
C signals on the pins SDA and SCL are toggled as illustrated in
Rev. 1 — 8 October 2009
2000 ns
Bit
7
0
0
1
x
x
x
x
x
x
1
1
1
1
1
0
x
[1]
6
0
0
x
x
x
x
x
x
x
x
x
x
x
x
x
x
5
0
0
x
x
x
x
x
x
x
x
x
x
x
x
x
x
4
0
0
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Real time clock and calendar
override active
3
1
0
x
x
x
x
x
x
x
x
x
x
x
x
x
x
PCF8564A
2
0
0
x
x
x
x
x
x
x
x
x
x
x
x
x
x
© NXP B.V. 2009. All rights reserved.
2
mgm664
C access. The
1
0
0
x
x
x
x
x
x
x
x
x
x
x
0
1
x
0
0
0
x
x
x
x
x
x
x
x
x
x
x
0
1
x
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