NXP Semiconductors
PCF2129T
Accurate RTC with integrated quartz crystal for industrial
8.8 Time and date function
Most of these registers are coded in the Binary Coded Decimal (BCD) format.
8.8.1 Register Seconds
Table 16. Seconds - seconds and clock integrity register (address 03h) bit description
Bit Symbol
Value Place value Description
7
OSF
0
-
clock integrity is guaranteed
1[1]
-
clock integrity is not guaranteed:
oscillator has stopped and chip reset
has occurred since flag was last cleared
6 to 4 SECONDS
0 to 5
ten’s place actual seconds coded in BCD format
3 to 0
0 to 9
unit place
[1] Start-up value.
Table 17. Seconds coded in BCD format
Seconds value in Upper-digit (ten’s place)
decimal
Bit 6
Bit 5
Bit 4
00
0
0
0
01
0
0
0
02
0
0
0
:
:
:
:
09
0
0
0
10
0
0
1
:
:
:
:
58
1
0
1
59
1
0
1
Digit (unit place)
Bit 3
Bit 2
0
0
0
0
0
0
:
:
1
0
0
0
:
:
1
0
1
0
Bit 1
0
0
1
:
0
0
:
0
0
Bit 0
0
1
0
:
1
0
:
0
1
8.8.2 Register Minutes
Table 18. Minutes - minutes register (address 04h) bit description
Bit Symbol
Value Place value Description
7
-
-
-
unused
6 to 4 MINUTES
0 to 5
ten’s place actual minutes coded in BCD format
3 to 0
0 to 9
unit place
PCF2129T
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 February 2013
© NXP B.V. 2013. All rights reserved.
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