mc9s12hz256v2 Freescale Semiconductor, Inc, mc9s12hz256v2 Datasheet - Page 189

• Manufacturer Part Number: mc9s12hz256v2
• Description: Hcs12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

5.4.6
The RTI can be used to generate a hardware interrupt at a fixed periodic rate. If enabled (by setting
RTIE=1), this interrupt will occur at the rate selected by the RTICTL register. The RTI runs with a gated
OSCCLK (see
RTIF flag is set to 1 and a new RTI time-out period starts immediately.
A write to the RTICTL register restarts the RTI time-out period.
If the PRE bit is set, the RTI will continue to run in pseudo-stop mode.
5.4.7
5.4.7.1
The CRG block behaves as described within this specification in all normal modes.
5.4.7.2
The VCO has a minimum operating frequency, f
to a failure or due to long crystal start-up time, the bus clock and the core clock are derived from the VCO
Freescale Semiconductor
Real-Time Interrupt (RTI)
Modes of Operation
Normal Mode
Self-Clock Mode
Section Figure 5-22., “Clock Chain for
gating condition
OSCCLK
= Clock Gate
STOP(PSTP,PRE),
WAIT(RTIWAI),
RTI enable
MC9S12HZ256 Data Sheet, Rev. 2.05
Figure 5-22. Clock Chain for RTI
2
2
2
2
2
2
SCM
1024
.
. If the external clock frequency is not available due
RTR[6:4]
0:1:0
0:0:1
0:1:1
1:0:0
1:0:1
1:1:0
1:1:1
0:0:0
RTI”). At the end of the RTI time-out period the
COUNTER (RTR[3:0])
4-BIT MODULUS
Chapter 5 Clocks and Reset Generator (CRGV4)
RTI TIMEOUT
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