Microchip Technology MA180025 データシート
2010 Microchip Technology Inc.
DS39933D-page 165
PIC18F87J90 FAMILY
15.1.4
RTCEN BIT WRITE
An attempt to write to the RTCEN bit while
RTCWREN = 0 will be ignored. RTCWREN must be
set before a write to RTCEN can take place.
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.
RTCWREN = 0 will be ignored. RTCWREN must be
set before a write to RTCEN can take place.
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.
15.2
Operation
15.2.1
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 Figure 15-2 and Figure 15-3).
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 15-2 and Figure 15-3).
FIGURE 15-2:
TIMER DIGIT FORMAT
FIGURE 15-3:
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