MC9S12P128_10 Datasheet, PDF (223/566 Pages) Freescale Semiconductor, Inc – S12 Microcontrollers

S12 Clock, Reset and Power Management Unit (S12CPMU)
7.3.2.15 Autonomous Periodical Interrupt Control Register (CPMUAPICTL)
The CPMUAPICTL register allows the configuration of the autonomous periodical interrupt features.
0x02F2
R
W
Reset
7
6
0
APICLK
5
4
3
2
1
0
APIES
APIEA
APIFE
APIE
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 7-18. Autonomous Periodical Interrupt Control Register (CPMUAPICTL)
Read: Anytime
Write: Anytime
Table 7-15. CPMUAPICTL Field Descriptions
0
APIF
0
Field
7
APICLK
4
APIES
3
APIEA
2
APIFE
1
APIE
0
APIF
Description
Autonomous Periodical Interrupt Clock Select Bit — Selects the clock source for the API. Writable only if
APIFE = 0. APICLK cannot be changed if APIFE is set by the same write operation.
0 Autonomous periodical interrupt clock used as source.
1 Bus Clock used as source.
Autonomous Periodical Interrupt External Select Bit — Selects the waveform at the external pin
API_EXTCLK as shown in Figure 7-19. See device level specification for connectivity of API_EXTCLK pin.
0 If APIEA and APIFE are set, at the external pin API_EXTCLK periodic high pulses are visible at the end of
every selected period with the size of half of the min period (APIR=0x0000 in Table 7-19).
1 If APIEA and APIFE are set, at the external pin API_EXTCLK a clock is visible with 2 times the selected API
Period.
Autonomous Periodical Interrupt External Access Enable Bit — If set, the waveform selected by bit APIES
can be accessed externally. See device level specification for connectivity.
0 Waveform selected by APIES can not be accessed externally.
1 Waveform selected by APIES can be accessed externally, if APIFE is set.
Autonomous Periodical Interrupt Feature Enable Bit — Enables the API feature and starts the API timer
when set.
0 Autonomous periodical interrupt is disabled.
1 Autonomous periodical interrupt is enabled and timer starts running.
Autonomous Periodical Interrupt Enable Bit
0 API interrupt request is disabled.
1 API interrupt will be requested whenever APIF is set.
Autonomous Periodical Interrupt Flag — APIF is set to 1 when the in the API configured time has elapsed.
This flag can only be cleared by writing a 1. Writing a 0 has no effect. If enabled (APIE = 1), APIF causes an
interrupt request.
0 API time-out has not yet occurred.
1 API time-out has occurred.
S12P-Family Reference Manual, Rev. 1.13
Freescale Semiconductor
223