Datasheet

Chapter 5 Resets, Interrupts, and General System Control
MC9S08QD4 Series MCU Data Sheet, Rev. 6
Freescale Semiconductor 63
5.8.7 System Real-Time Interrupt Status and Control Register (SRTISC)
This high-page register contains status and control bits for the RTI.
76543210
R ID7 ID6 ID5 ID4 ID3 ID2 ID1 ID0
W
Reset:00001001
= Unimplemented or Reserved
Figure 5-8. System Device Identification Register — Low (SDIDL)
Table 5-9. SDIDL Register Field Descriptions
Field Description
7:0
ID[7:0]
Part Identification Number — Each derivative in the HCS08 family has a unique identification number. The
MC9S08QD4 series is hard coded to the value 0x011. See also ID bits in Tabl e 5-8 .
76543210
RRTIF 0
RTICLKS RTIE
0
RTIS
W RTIACK
Reset:00000000
= Unimplemented or Reserved
Figure 5-9. System RTI Status and Control Register (SRTISC)
Table 5-10. SRTISC Register Field Descriptions
Field Description
7
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.
6
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 0.
5
RTICLKS
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 32 kHz ICS clock.
4
RTIE
Real-Time Interrupt Enable — This read-write bit enables real-time interrupts.
0 Real-time interrupts disabled.
1 Real-time interrupts enabled.
2:0
RTIS
Real-Time Interrupt Delay Selects — These read/write bits select the period for the RTI. See Tabl e 5 -1 1