Datasheet

 2008-2011 Microchip Technology Inc. DS39927C-page 157
PIC24F16KA102 FAMILY
19.2.4 RTCC CONTROL REGISTERS
REGISTER 19-1:
RCFGCAL: RTCC CALIBRATION AND CONFIGURATION REGISTER
( 1)
R/W-0 U-0 R/W-0 R-0, HSC R-0, HSC R/W-0 R/W-0 R/W-0
RTCEN
(2)
— RTCWREN RTCSYNC HALFSEC
(3)
RTCOE RTCPTR1 RTCPTR0
bit 15 bit 8
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
CAL7 CAL6 CAL5 CAL4 CAL3 CAL2 CAL1 CAL0
bit 7 bit 0
Legend: HSC = Hardware Settable/Clearable bit
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 15 RTCEN: RTCC Enable bit
(2)
1 = RTCC module is enabled
0 = RTCC module is disabled
bit 14 Unimplemented: Read as ‘0’
bit 13 RTCWREN: RTCC Value Registers Write Enable bit
1 = RTCVALH and RTCVALL registers can be written to by the user
0 = RTCVALH and RTCVALL registers are locked out from being written to by the user
bit 12 RTCSYNC: RTCC Value Registers Read Synchronization bit
1 = RTCVALH, RTCVALL and ALCFGRPT registers can change while reading due to a rollover ripple,
resulting in an invalid data read. If the register is read twice and results in the same data, the data
can be assumed to be valid.
0 = RTCVALH, RTCVALL or ALCFGRPT registers can be read without concern over a rollover ripple
bit 11 HALFSEC: Half Second Status bit
(3)
1 = Second half period of a second
0 = First half period of a second
bit 10 RTCOE: RTCC Output Enable bit
1 = RTCC output is enabled
0 = RTCC output is disabled
bit 9-8 RTCPTR<1:0>: RTCC Value Register Window Pointer bits
Points to the corresponding RTCC Value registers when reading the RTCVALH and RTCVALL registers.
The RTCPTR<1:0> value decrements on every read or write of RTCVALH until it reaches ‘00’.
RTCVAL<15:8>:
00 = MINUTES
01 = WEEKDAY
10 = MONTH
11 = Reserved
RTCVAL<7:0>:
00 = SECONDS
01 = HOURS
10 = DAY
11 = YEAR
Note 1: The RCFGCAL register is only affected by a POR.
2: A write to the RTCEN bit is only allowed when RTCWREN = 1.
3: This bit is read-only; it is cleared to ‘0’ on a write to the lower half of the MINSEC register.