
Clocks, Reset, and Power (CRP)
PXN20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor
6-27
the 32 kHz OSC must be enabled before being selected. The 32 kHz OSC is selected to give a more
accurate wakeup than the 128 kHz IRC. (CNTEN must be disabled when the clock sources are switched.)
When the counter value for counter bits 10–21 match the 12-bit value in RTCVAL, then the RTCF interrupt
flag is set (after proper clock synchronization). If the RTCIE interrupt enable bit is set, the RTC interrupt
request is generated. The RTCF flag can be cleared by writing a 1 to RTCF. The RTCF supports interrupt
requests in the range of 1 second to 4096 seconds (> 1 hr) with a 1 second resolution.
NOTE
RTCVAL and APIVAL can be updated at any time.
If there is a match while in sleep mode, and the CRP_PSCR[RTCWKEN] bit is set, then the RTC first
generates a wakeup request to force a wakeup to run mode, then sets the RTCF flag. The RTC wakeup
signal is captured in the CRP_PSCR[WKRTCF] flag bit.
A rollover wakeup and/or interrupt can be generated when the RTC transitions from a count of
0xFFFF_FFFF to 0x0000_0000. The rollover flag is enabled by setting the CRP_RTCC[ROVREN] bit.
An RTC counter rollover with this bit and the CRP_PSCR[RTCOVRWKEN] bit set causes a wakeup from
sleep mode. The rollover wakeup flag is captured in the CRP_PSCR[WKRLLOVRF] bit. An interrupt
request is generated for an RTC counter rollover when both the CRP_RTCC[ROVREN] and
CRP_RTCC[RTCIE] bits are set.
Setting APIEN enables the autonomous interrupt function. The 10 bit APIVAL selects the time interval for
triggering an interrupt and/or wakeup event. Since the RTC is a free-running counter, the APIVAL is added
to the current count to calculate an offset. When the counter reaches the offset count, a interrupt and/or
wakeup request is generated. Then the offset value is recalculated and again retriggers a new request when
the new value is reached. APIVAL (and RTCVAL) can be updated at any time. When a compare is reached,
the APIF interrupt flag is set (after proper clock synchronization). If the APIIE interrupt enable bit is set,
then the API interrupt request is generated. The APIF flag can be cleared by writing a 1 to APIF. If there
is a match while in sleep mode, and the CRP_PSCR[APIWKEN] bit is set, then the API first generates a
wakeup request to force a wakeup to run mode, then sets the APIF flag. The API wakeup flag is captured
in the CRP_PSCR[WKAPIF] bit.
If the CRP_RTCC[FRZEN] bit is set, the RTC counter is frozen during debug mode.
Содержание PXN2020
Страница 1: ...PXN20 Microcontroller Reference Manual Devices Supported PXN2020 PXN2120 PXN20RM Rev 1 06 2011...
Страница 42: ...PXN20 Microcontroller Reference Manual Rev 1 lxiv Freescale Semiconductor...
Страница 64: ...Introduction PXN20 Microcontroller Reference Manual Rev 1 1 22 Freescale Semiconductor...
Страница 112: ...Signal Description PXN20 Microcontroller Reference Manual Rev 1 3 44 Freescale Semiconductor...
Страница 118: ...Resets PXN20 Microcontroller Reference Manual Rev 1 4 6 Freescale Semiconductor...
Страница 162: ...Clocks Reset and Power CRP PXN20 Microcontroller Reference Manual Rev 1 6 30 Freescale Semiconductor...
Страница 182: ...Frequency Modulated Phase Locked Loop FMPLL PXN20 Microcontroller Reference Manual Rev 1 7 20 Freescale Semiconductor...
Страница 268: ...Boot Assist Module BAM PXN20 Microcontroller Reference Manual Rev 1 9 14 Freescale Semiconductor...
Страница 318: ...Interrupts and Interrupt Controller INTC PXN20 Microcontroller Reference Manual Rev 1 10 50 Freescale Semiconductor...
Страница 326: ...General Purpose Static RAM SRAM PXN20 Microcontroller Reference Manual Rev 1 11 8 Freescale Semiconductor...
Страница 372: ...e200z6 Core Z6 PXN20 Microcontroller Reference Manual Rev 1 13 8 Freescale Semiconductor...
Страница 412: ...e200z0 Core Z0 PXN20 Microcontroller Reference Manual Rev 1 14 14 Freescale Semiconductor...
Страница 460: ...Memory Protection Unit MPU PXN20 Microcontroller Reference Manual Rev 1 18 20 Freescale Semiconductor...
Страница 478: ...Error Correction Status Module ECSM PXN20 Microcontroller Reference Manual Rev 1 19 18 Freescale Semiconductor...
Страница 488: ...Software Watchdog Timer SWT PXN20 Microcontroller Reference Manual Rev 1 20 10 Freescale Semiconductor...
Страница 494: ...System Timer Module STM PXN20 Microcontroller Reference Manual Rev 1 21 6 Freescale Semiconductor...
Страница 821: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 Freescale Semiconductor 27 49...
Страница 822: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 27 50 Freescale Semiconductor...
Страница 926: ...Controller Area Network FlexCAN PXN20 Microcontroller Reference Manual Rev 1 29 42 Freescale Semiconductor...
Страница 990: ...Deserial Serial Peripheral Interface DSPI PXN20 Microcontroller Reference Manual Rev 1 30 64 Freescale Semiconductor...
Страница 1044: ...Enhanced Serial Communication Interface eSCI PXN20 Microcontroller Reference Manual Rev 1 31 54 Freescale Semiconductor...
Страница 1080: ...Cross Triggering Unit CTU PXN20 Microcontroller Reference Manual Rev 1 33 12 Freescale Semiconductor...
Страница 1134: ...Analog to Digital Converter ADC PXN20 Microcontroller Reference Manual Rev 1 34 54 Freescale Semiconductor...
Страница 1150: ...IEEE 1149 1 Test Access Port Controller JTAGC PXN20 Microcontroller Reference Manual Rev 1 35 16 Freescale Semiconductor...
Страница 1257: ...Nexus Development Interface NDI PXN20 Microcontroller Reference Manual Rev 1 Freescale Semiconductor 36 107...
Страница 1258: ...Nexus Development Interface NDI PXN20 Microcontroller Reference Manual Rev 1 36 108 Freescale Semiconductor...
Страница 1376: ...Memory Map PXN20 Microcontroller Reference Manual Rev 1 A 118 Freescale Semiconductor...