pcf2123 NXP Semiconductors, pcf2123 Datasheet - Page 11

• Manufacturer Part Number: pcf2123
• Description: Spi Real Time Clock/calendar
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCF2123_1
Product data sheet
9.3.2 Register Control_2
9.4 OS flag
Table 6.
The PCF2123 includes a flag (bit OS) which is set whenever the oscillator is stopped (see
Figure 8
be cleared, then the PCF2123 oscillator is not running. This method can be used to
monitor the oscillator and to determine if the supply voltage has reduced to the point
where oscillation fails.
Bit
7
6
5
4
3
2
1
0
Fig 8.
Symbol
MI
SI
MSF
TI_TP
AF
TF
AIE
TIE
and
OS set by failing V
Register Control_2 (address 01h) bits description
Figure
V
OSC(MIN)
9). The flag will remain set until cleared by software. If the flag cannot
Rev. 01 — 19 November 2008
V
DD
Value
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
DD
battery operation
Description
minute interrupt is disabled
minute interrupt is enabled
second interrupt is disabled
second interrupt is enabled
no minute or second interrupt generated
flag set when minute or second interrupt
generated;
interrupt pin follows timer flags
interrupt pin generates a pulse
no alarm interrupt generated
flag set when alarm triggered;
no countdown timer interrupt generated
flag set when countdown timer interrupt
generated;
no interrupt generated from the alarm flag
interrupt generated when alarm flag set
no interrupt generated from the countdown
timer
interrupt generated by the countdown timer
flag must be cleared to clear interrupt
when TI_IP = 0
flag must be cleared to clear interrupt
flag must be cleared to clear interrupt
when TI_IP = 0
main supply
SPI Real time clock/calendar
001aai561
PCF2123
t
© NXP B.V. 2008. All rights reserved.
Reference
Section 9.8.1
Section 9.9.2
Section 9.7.1
-
Section 9.9.3
Section 9.9.2
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