Freescale Semiconductor Demonstration Board for Freescale MC9S12XHY256 Microcontroller DEMO9S12XHY256 DEMO9S12XHY256 Manuale Utente
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DEMO9S12XHY256
Voltage Regulator (S12VREGL3V3V1)
MC9S12XHY-Family Reference Manual Rev. 1.04
Freescale Semiconductor
303
9.3.2.3
Autonomous Periodical Interrupt Control Register (VREGAPICL)
The VREGAPICL register allows the configuration of the VREG_3V3 autonomous periodical interrupt
features.
features.
0x02F2
7
6
5
4
3
2
1
0
R
APICLK
0
0
APIES
APIEA
APIFE
APIE
APIF
W
Reset
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 9-3. Autonomous Periodical Interrupt Control Register (VREGAPICL)
Table 9-6. VREGAPICL Field Descriptions
Field
Description
7
APICLK
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.
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.
4
APIES
Autonomous Periodical Interrupt External Select Bit — Selects the waveform at the external pin.If set, at the
external pin a clock is visible with 2 times the selected API Period (
external pin a clock is visible with 2 times the selected API Period (
). If not set, at the external pin will
be a high pulse at the end of every selected period with the size of half of the min period (
). See device
level specification for connectivity.
0 At the external periodic high pulses are visible, if APIEA and APIFE is set.
1 At the external pin a clock is visible, if APIEA and APIFE is set.
0 At the external periodic high pulses are visible, if APIEA and APIFE is set.
1 At the external pin a clock is visible, if APIEA and APIFE is set.
3
APIEA
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.
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.
2
APIFE
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.
when set.
0 Autonomous periodical interrupt is disabled.
1 Autonomous periodical interrupt is enabled and timer starts running.
1
APIE
Autonomous Periodical Interrupt Enable Bit
0 API interrupt request is disabled.
1 API interrupt will be requested whenever APIF is set.
0 API interrupt request is disabled.
1 API interrupt will be requested whenever APIF is set.
0
APIF
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 to it. Clearing of the flag has precedence over setting.
Writing a 0 has no effect. If enabled (APIE = 1), APIF causes an interrupt request.
0 API timeout has not yet occurred.
1 API timeout has occurred.
This flag can only be cleared by writing a 1 to it. Clearing of the flag has precedence over setting.
Writing a 0 has no effect. If enabled (APIE = 1), APIF causes an interrupt request.
0 API timeout has not yet occurred.
1 API timeout has occurred.