mc9s08gt32a Freescale Semiconductor, Inc, mc9s08gt32a Datasheet - Page 76

• Manufacturer Part Number: mc9s08gt32a
• Description: Hcs08 Microcontrollers 8-bit Microcontroller Family
• Manufacturer: Freescale Semiconductor, Inc

Chapter 5 Resets, Interrupts, and System Configuration
5.8.6
This register contains one read-only status flag, one write-only acknowledge bit, three read/write delay
selects, and three unimplemented bits, which always read 0.
1
2
76
RTICLKS
RTIS[2:0]
See
t
Reset
RTIACK
ext
Field
RTIE
RTIF
2:0
is based on the external clock source, resonator, or crystal selected by the ICG configuration. See
7
6
5
4
W
Table
R
RTIS2:RTIS1:RTIS0
A-10t
System Real-Time Interrupt Status and Control Register (SRTISC)
RTIF
Real-Time Interrupt Flag — This read-only status bit indicates the periodic wakeup timer has timed out.
0 Periodic wakeup timer not timed out.
1 Periodic wakeup timer timed out.
Real-Time Interrupt Acknowledge — This write-only bit is used to acknowledge real-time interrupt request
(write 1 to clear RTIF). Writing 0 has no meaning or effect. Reads always return 0.
Real-Time Interrupt Clock Select — This read/write bit selects the clock source for the real-time interrupt.
0 Real-time interrupt request clock source is internal oscillator.
1 Real-time interrupt request clock source is external clock.
Real-Time Interrupt Enable — This read-write bit enables real-time interrupts.
0 Real-time interrupts disabled.
1 Real-time interrupts enabled.
Real-Time Interrupt Period Selects — These read/write bits select the wakeup period for the RTI. One clock
source for the real-time interrupt is its own internal clock source, which oscillates with a period of approximately
t
frequency divided by value in RTIS2:RTIS1:RTIS0. See
RTI
0
7
0:0:0
0:0:1
0:1:0
0:1:1
1:0:0
1:0:1
1:1:0
1:1:1
RTI
and is independent of other MCU clock sources. Using an external clock source the delays will be crystal
in
= Unimplemented or Reserved
Appendix A, “Electrical
Figure 5-8. System RTI Status and Control Register (SRTISC)
RTIACK
0
0
6
Table 5-8. SRTISC Field Descriptions
RTICLKS
Table 5-9. Real-Time Interrupt Period
MC9S08GB60A Data Sheet, Rev. 1.02
0
5
Disable periodic wakeup timer
Characteristics,” for the tolerance on these values.
Internal Clock Source
(t
RTI
= 1 ms, Nominal)
RTIE
128 ms
256 ms
512 ms
1.024 s
32 ms
64 ms
0
4
8 ms
Description
Table
1
3
0
0
5-9.
RTIS2
0
2
Disable periodic wakeup timer
External Clock Source
Period = t
t
t
t
ext
t
t
t
ex
t
ext
ex
ex
ex
Freescale Semiconductor
ext
RTIS
x 32768
x 16384
x 1024
x 2048
x 4096
x 8192
Table A-9
0
x 256
1
1
ext
for details.
RTIS
2
0
0
0