pcf2127a NXP Semiconductors, pcf2127a Datasheet - Page 46

• Manufacturer Part Number: pcf2127a
• Description: Integrated Rtc, Tcxo And Quartz Crystal
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCF2127A_1
Product data sheet
The minute/second flag MSF (register Control_2) is set logic 1 when either the seconds or
the minutes counter increments according to the actually enabled interrupt (see
The MSF flag can be read and cleared by the interface.
Table 53.
When MSF is set logic 1:
MI SI Result on INT
0
1
0
1
Fig 26. INT example for SI and MI when TI_TP is logic 1
•
•
If TI_TP is logic 1 the interrupt is generated as a pulsed signal.
If TI_TP is logic 0 the interrupt is permanently active signal that remains until MSF is
cleared.
0
0
1
1
MSF when only MI enabled
INT when only MI enabled
MSF when SI enabled
no interrupt generated
an interrupt once per minute
an interrupt once per second
an interrupt once per second
INT when SI enabled
In this example, bit TI_TP is logic 1 and the MSF flag is not cleared after an interrupt.
Effect of bits MI and SI on pin INT and bit MSF
seconds counter
minutes counter
Rev. 01 — 21 January 2010
58
59
Result on MSF
MSF never set
MSF set when minutes counter increments
MSF set when seconds counter increments
MSF set when seconds counter increments
Integrated RTC, TCXO and quartz crystal
59
11
00
12
PCF2127A
00
© NXP B.V. 2010. All rights reserved.
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53).