PCF8563TS Philips Semiconductors, PCF8563TS Datasheet - Page 5

• Manufacturer Part Number: PCF8563TS
• Description: Real-time clock/calendar
• Manufacturer: Philips Semiconductors

Philips Semiconductors
Table 4:
Bit positions labelled as ‘ ’are not implemented; those labelled with ‘0’ should always be written with logic 0.
9397 750 04855
Product specification
Address Register name
00H
01H
0DH
0EH
0FH
Registers overview
Control/Status 1
Control/Status 2
CLKOUT frequency
Timer control
Timer countdown
value
8.4 Reset
8.5 Voltage-low detector and clock monitor
8.6 Register organization
The PCF8563 includes an internal reset circuit which is active whenever the oscillator
is stopped. In the reset state the I
the address pointer, are cleared with the exception of bits FE, VL, TD1, TD0, TESTC
and AE which are set to logic 1.
The PCF8563 has an on-chip voltage-low detector. When V
VL bit (Voltage Low, bit 7 in the Seconds register) is set to indicate that reliable
clock/calendar information is no longer guaranteed. The VL flag can only be cleared
by software.
The VL bit is intended to detect the situation when V
example under battery operation. Should V
then the VL bit will be set. This will indicate that the time may be corrupted.
Fig 4. Voltage-low detection.
TEST1
Bit 7
FE
TE
0
Bit 6
0
0
handbook, halfpage
V DD
16 April 1999
V low
STOP
Bit 5
0
<timer countdown value>
2
C-bus logic is initialized and all registers, including
period of battery
operation
TI/TP
Bit 4
0
DD
TESTC
reach V
Bit 3
VL set
AF
normal power
operation
DD
low
MGR887
is decreasing slowly for
Bit 2
t
before power is re-asserted
TF
0
Real-time clock/calendar
© Philips Electronics N.V. 1999. All rights reserved.
DD
drops below V
PCF8563
Bit 1
FD1
TD1
AIE
0
low
Bit 0
FD0
TD0
TIE
0
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the