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System Clock Description
PXN20 Microcontroller Reference Manual, Rev. 1
5-4
Freescale Semiconductor
— jitter < 0.5%
— duty cycle: 50% ±10%
•
Clock source can be kept alive in Sleep mode to facilitate fast start up. However, if > 8 MHz is
required, it cannot drive the RTC/API as the output driver needs to be disabled.
•
Can be stopped in low power mode to reduce current consumption
•
PLL Off mode to reduce consumption with external clock
•
External square-wave input with PLL Off mode XTAL enabled by default out of Reset, turned off
for Square wave i/p
5.1.4
Internal High-Frequency RC Oscillator (16 MHz_IRC)
This internal RC oscillator provides a 16 MHz clock source to the device. The initial trimming value is
copied into the trimming register during power on reset (POR). The device’s individual value is
determined during one of the silicon test steps and stored in the device test Flash block. Until the Flash is
up and stable, the IRC runs at its untrimmed frequency.
5.1.4.1
16 MHz_IRC Features
•
16 MHz_IRC is the default system clock out of reset. This clock features the following:
— Clock for rapid startup from low power modes
— Can be configured to run in Sleep mode
— Backup clock in case of external oscillator or PLL failure
•
Fast stabilization, enabling fast recovery
•
Frequency trimmable for accuracy
•
Powered from V
RC
(3.3 V or 5 V nominal)
•
Always enabled except in sleep modes when not being used (disabled in hardware only)
•
The 16 MHz_IRC block contains no dividers of its own.
5.1.5
Internal Low-Frequency RC Oscillator (128 kHz_IRC)
The PXN20 includes a 128 kHz internal RC oscillator that is a highly reliable clock source during
low-power modes. This internal RC oscillator provide a 128 kHz clock source to the device. The initial
trimming value is copied into the trimming register during power on reset. This device’s individual value
is determined during one of the silicon test steps and stored in the device test Flash block. This trim value
is retained through Sleep mode.
5.1.5.1
128 kHz_IRC Features
The 128 kHz_IRC clock features the following:
•
Frequency trimmable for accuracy
•
Option to clock the API to provide a wakeup
•
Option to clock the RTC to provide timekeeping
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...