MC9S08AC16_0911 Datasheet, PDF (76/336 Pages) Freescale Semiconductor, Inc – HCS08 Microcontrollers

Chapter 5 Resets, Interrupts, and System Configuration
R
W
Reset
Field
7:0
ID[7:0]
7
6
5
4
3
2
1
0
ID7
ID6
ID5
ID4
ID3
ID2
ID1
ID0
0
0
0
1
0
0
1
0
= Unimplemented or Reserved
Figure 5-8. System Device Identification Register — Low (SDIDL)
Table 5-9. SDIDL Register Field Descriptions
Description
Part Identification Number — Each derivative in the HCS08 Family has a unique identification number. The
MC9S08AC16 Series is hard coded to the value 0x012. See also ID bits in Table 5-8.
5.9.7 System Real-Time Interrupt Status and Control Register (SRTISC)
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.
R
W
Reset
7
RTIF
0
6
0
RTIACK
5
RTICLKS
4
RTIE
3
2
1
0
RTIS2
RTIS1
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 5-9. System RTI Status and Control Register (SRTISC)
0
RTIS0
0
Table 5-10. SRTISC Register Field Descriptions
Field
Description
7
RTIF
6
RTIACK
5
RTICLKS
4
RTIE
2:0
RTIS[2:0]
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 logic 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 1-kHz 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 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 which oscillates at about 1 kHz, is independent of other
MCU clock sources. Using external clock source the delays will be crystal frequency divided by value in
RTIS2:RTIS1:RTIS0. See Table 5-11.
MC9S08AC16 Series Data Sheet, Rev. 8
76
Freescale Semiconductor