Datasheet
PCF85063TP All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
Product data sheet Rev. 3 — 11 July 2013 16 of 47
NXP Semiconductors
PCF85063TP
Tiny Real-Time Clock/calendar
8.2.4 Register RAM_byte
The PCF85063TP provides a free RAM byte, which can be used for any purpose, for
example, status byte of the system.
[1] Default value.
8.3 Time and date registers
Most of the registers are coded in the BCD format to simplify application use.
8.3.1 Register Seconds
[1] Default value.
With the offset calibration an accuracy of 2 ppm (0.5 offset per LSB) can be reached (see
Table 13
).
1 ppm corresponds to a time deviation of 0.0864 seconds per day.
(1) 3 correction pulses in MODE = 0 correspond to 13.02 ppm.
(2) 4 correction pulses in MODE = 1 correspond to 16.276 ppm.
(3) Reachable accuracy zone.
Fig 9. Result of offset calibration
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Table 18. RAM_byte - 8-bit RAM register (address 03h) bit description
Bit Symbol Value Description
7 to 0 B[7:0] 00000000
[1]
to
11111111
RAM content
Table 19. Seconds - seconds register (address 04h) bit description
Bit Symbol Value Place value Description
7OS oscillator stop
0 - clock integrity is guaranteed
1
[1]
- clock integrity is not
guaranteed; oscillator has
stopped or has been
interrupted
6to4 SECONDS 0
[1]
to 5 ten’s place actual seconds coded in BCD
format, see Table 20
3 to 0 0
[1]
to 9 unit place