Datasheet

PCF2127AT All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
Product data sheet Rev. 6 — 11 July 2013 44 of 86
NXP Semiconductors
PCF2127AT
Integrated RTC, TCXO and quartz crystal
The TSF1 and TSF2 flags can be cleared by command; clearing both flags will clear
the interrupt. Once TSF2 is cleared, it will only be set again when TS
pin is driven to
ground once again.
8.12.2 Timestamp mode
The timestamp function has two different modes selected by the control bit TSM
(timestamp mode) in register Timestp_ctl:
• If TSM is logic 0 (default): in subsequent trigger events without clearing the timestamp
flags, the last timestamp event is stored
• If TSM is logic 1: in subsequent trigger events without clearing the timestamp flags,
the first timestamp event is stored
The timestamp function also depends on the control bit BTSE in register Control_3, see
Section 8.12.4
.
8.12.3 Timestamp registers
8.12.3.1 Register Timestp_ctl
[1] Default value.
8.12.3.2 Register Sec_timestp
8.12.3.3 Register Min_timestp
Table 46. Timestp_ctl - timestamp control register (address 12h) bit description
Bit Symbol Value Description
7TSM 0
[1]
in subsequent events without clearing the timestamp
flags, the last event is stored
1 in subsequent events without clearing the timestamp
flags, the first event is stored
6TSOFF 0
[1]
timestamp function active
1 timestamp function disabled
5 - - unused
4 to 0 1_O_16_TIMESTP[4:0]
1
⁄
16
second timestamp information coded in BCD format
Table 47. Sec_timestp - second timestamp register (address 13h) bit description
Bit Symbol Value Place value Description
7 - - - unused
6 to 4 SECOND_TIMESTP 0 to 5 ten’s place second timestamp information coded in
BCD format
3to0 0to9 unit place
Table 48. Min_timestp - minute timestamp register (address 14h) bit description
Bit Symbol Value Place value Description
7 - - - unused
6 to 4 MINUTE_TIMESTP 0 to 5 ten’s place minute timestamp information coded in
BCD format
3to0 0to9 unit place