Rtc Control Register; Rtc Interrupt Status Register; Table 23-9 Rtc Control Register Description - Motorola DragonBall MC9328MX1 Reference Manual

Real-Time Clock (RTC)

23.2.7 RTC Control Register

The real-time clock control (RTCCTL) register is used to enable the real-time clock module and specify
the reference frequency information for the prescaler.
RCCTL
BIT 31 30 29
TYPE r r r
0 0 0
RESET
BIT 15 14 13
TYPE r r r
0 0 0
RESET
Name
Reserved Reserved—These bits are reserved and should read 0.
Bits 31–8
EN Enable—Enables/Disables the real-time clock. The
Bit 7 software reset bit (SWR) has no effect on this bit.
XTL Crystal Selection—Selects the proper input crystal
Bits 6–5 frequency. It is important to set these bits correctly or the
real-time clock will be inaccurate.
Reserved Reserved—These bits are reserved and should read 0.
Bits 4–1
SWR Software Reset—Resets the module to its default state.
Bit 0 However, a software reset will have no effect on the clock
enable (EN) bit.

23.2.8 RTC Interrupt Status Register

The real-time clock interrupt status register (RTCISR) indicates the status of the various real-time clock
interrupts, except for the 2Hz bit. When an event of the types included in this register occurs, if the
corresponding bit in the RTC Interrupt Enable Register (RTCIENR) is set, then the bit will be set in this
register. These bits are cleared by writing a value of 1, which also clears the interrupt. Interrupts may occur
when the system clock is idle or in sleep mode. For more information about the frequency of the sampling
timer interrupts (SAM7-SAM0), refer to Table 23-1.
23-10
RTC Control Register
28 27 26 25
r r r r
0 0 0 0
12 11 10 9
r r r r
0 0 0 0
Table 23-9. RTC Control Register Description
Description
MC9328MX1 Reference Manual
24 23 22 21
r r r r
0 0 0 0
0x0000
8 7 6 5
EN XTL
r rw rw rw
0 1 0 0
0x0080
0 = Disable the real-time clock
1 = Enable the real-time clock
00 = 32.768 kHz
01 = 32 kHz
10 = 38.4 kHz
11 = 32.768 kHz
0 = No effect.
1 = Reset the module to its default
state.
Addr
0x00204010
20 19 18 17
r r r r
0 0 0 0
4 3 2 1
SWR
r r r r
0 0 0 0
Settings
MOTOROLA
16
r
0
0
rw
0