Техническая Спецификация для Microchip Technology ARD00385
2009-2011 Microchip Technology Inc.
DS39957D-page 229
PIC18F87K90 FAMILY
17.1.4
RTCEN BIT WRITE
RTCWREN (RTCCFG<5>) must be set before a write
to RTCEN can take place. Any write to the RTCEN bit,
while RTCWREN = 0, will be ignored.
Like the RTCEN bit, the RTCVALH and RTCVALL
registers can only be written to when RTCWREN = 1.
A write to these registers, while RTCWREN = 0, will be
ignored.
to RTCEN can take place. Any write to the RTCEN bit,
while RTCWREN = 0, will be ignored.
Like the RTCEN bit, the RTCVALH and RTCVALL
registers can only be written to when RTCWREN = 1.
A write to these registers, while RTCWREN = 0, will be
ignored.
17.2
Operation
17.2.1
REGISTER INTERFACE
The register interface for the RTCC and alarm values is
implemented using the Binary Coded Decimal (BCD)
format. This simplifies the firmware when using the
module as each of the digits is contained within its own
4-bit value (see
implemented using the Binary Coded Decimal (BCD)
format. This simplifies the firmware when using the
module as each of the digits is contained within its own
4-bit value (see
FIGURE 17-2:
TIMER DIGIT FORMAT
FIGURE 17-3:
ALARM DIGIT FORMAT
0-6
0-9
0-9
0-3
0-9
0-9
0-9
0-9
0-2
0-5
0-5
0/1
Day of Week
Year
Day
Hours
(24-hour format)
Minutes
Seconds
1/2 Second Bit
0-1
0-9
Month
(binary format)
0-6
0-3
0-9
0-9
0-9
0-9
0-2
0-5
0-5
Day of Week
Day
Hours
(24-hour format)
Minutes
Seconds
0-1
0-9
Month