Rtc Control Register; Rtc Interrupt Status Register; Table 11-7 Rtc Control Register Description - Motorola MC68VZ328 User Manual

Programming Model
11.2.6

RTC Control Register

The real-time clock control (RTCCTL) register is used to enable the real-time clock and provide reference
frequency information to the prescaler. The settings for the RTCCTL register are described in Table 11-7.
RTCCTL
BIT
14 13
15
TYPE
0 0 0
RESET
Name
Reserved Reserved
Bits 15–8
RTCEN Real-Time Clock Enable—This bit, when set,
Bit 7 enables the real-time clock.
Reserved Reserved
Bit 6
REFREQ Reference Frequency—This bit is set to the fre-
Bit 5 quency of the crystal oscillator.
Reserved Reserved
Bits 4–0
11.2.7

RTC Interrupt Status Register

The real-time clock interrupt status register (RTCISR) indicates the status of the various real-time clock
interrupts. Each bit is set when the corresponding event occurs. You must clear these bits by writing ones,
which also clears the interrupt. This register can post interrupts while the system clock is idle or in sleep
mode. The settings for the RTCISR register are described in Table 11-8 on page 11-11. For more
information about the frequency of the RTC interrupts, refer to Table 11-9 on page 11-12.
11-10
RTC Control Register
12 11 10 9 8
0 0 0 0 0
Table 11-7. RTC Control Register Description
Description
MC68VZ328 User's Manual
7 6 5
RTCEN REFREQ
rw rw
1 0 0
0x0080
These bits are reserved and should be set to
0.
0 = Disable the real-time clock
1 = Enable the real-time clock (default)
This bit is reserved and should be set to 0.
0 = Reference frequency is 32.768 kHz
(default).
1 = Reference frequency is 38.4 kHz.
These bits are reserved and should be set to
0.
0x(ff)FFFB0C
BIT
4 3 2 1
0
0 0 0 0 0
Setting