MC9S08RG60 Datasheet, PDF (70/232 Pages) Motorola, Inc – Microcontrollers

Resets, Interrupts, and System Configuration
RTIF — Real-Time Interrupt Flag
This read-only status bit indicates the periodic wakeup timer has timed out.
1 = Periodic wakeup timer timed out.
0 = Periodic wakeup timer not timed out.
RTIACK — 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 logic 0.
RTICLKS — Real-Time Interrupt Clock Select
This read/write bit selects the clock source for the real-time interrupt.
1 = Real-time interrupt request clock source is external clock.
0 = Real-time interrupt request clock source is internal 1-kHz oscillator.
RTIE — Real-Time Interrupt Enable
This read-write bit enables real-time interrupts.
1 = Real-time interrupts enabled.
0 = Real-time interrupts disabled.
RTIS2:RTIS1:RTIS0 — Real-Time Interrupt Delay Selects
These read/write bits select the wakeup delay for the RTI. The clock source for the real-time interrupt
is a self-clocked source that oscillates at about 1 kHz and is independent of other MCU clock sources.
Using an external clock source, the delays will be crystal frequency divided by the value in
RTIS2:RTIS1:RTIS0.
Table 5-2 Real-Time Interrupt Frequency
RTIS2:RTIS1:RTIS0
1-kHz Clock Source Delay⁽¹⁾
Using External Clock Source Delay
(crystal frequency)
0:0:0
Disable periodic wakeup timer
Disable periodic wakeup timer
0:0:1
8 ms
divide by 256
0:1:0
32 ms
divide by 1024
0:1:1
64 ms
divide by 2048
1:0:0
128 ms
divide by 4096
1:0:1
256 ms
divide by 8192
1:1:0
512 ms
divide by 16384
1:1:1
1.024 s
divide by 32768
NOTES:
1. Normal values are shown in this column based on f_RTI = 1 kHz. See Table C-9 Control Timing f_RTI for the tolerance
on these values.
70
MC9S08RC/RD/RE/RG
Freescale Semiconductor