![NXP Semiconductors MPC5605BK Скачать руководство пользователя страница 913](http://html.mh-extra.com/html/nxp-semiconductors/mpc5605bk/mpc5605bk_reference-manual_1721852913.webp)
Chapter 33 Software Watchdog Timer (SWT)
MPC5606BK Microcontroller Reference Manual, Rev. 2
Freescale Semiconductor
913
Chapter 33
Software Watchdog Timer (SWT)
33.1
Overview
The SWT is a peripheral module that can prevent system lockup in situations such as software getting
trapped in a loop or if a bus transaction fails to terminate. When enabled, the SWT requires periodic
execution of a watchdog servicing sequence. Writing the sequence resets the timer to a specified time-out
period. If this servicing action does not occur before the timer expires the SWT generates an interrupt or
hardware reset. The SWT can be configured to generate a reset or interrupt on an initial time-out, a reset
is always generated on a second consecutive time-out.
The SWT provides a window functionality. When this functionality is programmed, the servicing action
should take place within the defined window. When occurring outside the defined period, the SWT
generates a reset.
33.2
Features
The SWT has the following features:
•
32-bit time-out register to set the time-out period
•
The unique SWT counter clock is the undivided slow internal RC oscillator 128 kHz (SIRC), no
other clock source can be selected
•
Programmable selection of window mode or regular servicing
•
Programmable selection of reset or interrupt on an initial time-out
•
Master access protection
•
Hard and soft configuration lock bits
•
The SWT is started on exit of power-on phase (RGM phase 2) to monitor flash boot sequence
phase. It is then reset during RGM phase3 and optionally enabled when platform reset is released
depending on value of flash user option bit 31 (WATCHDOG_EN).
33.3
Modes of operation
The SWT supports three device modes of operation: normal, debug, and stop. When the SWT is enabled
in normal mode, its counter runs continuously. In debug mode, operation of the counter is controlled by
the FRZ bit in the SWT_CR. If the FRZ bit is set, the counter is stopped in debug mode, otherwise it
continues to run. In STOP mode, operation of the counter is controlled by the STP bit in the SWT_CR. If
the STP bit is set, the counter is stopped in STOP mode, otherwise it continues to run. On exit from STOP
mode, the SWT will continue from the state it was before entering this mode.
The software watchdog is not available during standby. On exit from standby, the SWT behaves in a usual
“out of reset” situation.
Содержание MPC5605BK
Страница 2: ...This page is intentionally left blank...
Страница 20: ...MPC5606BK Microcontroller Reference Manual Rev 2 20 Freescale Semiconductor...
Страница 103: ...MPC5606BK Microcontroller Reference Manual Rev 2 Freescale Semiconductor 103 Clocks and power...
Страница 104: ...MPC5606BK Microcontroller Reference Manual Rev 2 104 Freescale Semiconductor This page is intentionally left blank...
Страница 243: ...MPC5606BK Microcontroller Reference Manual Rev 2 Freescale Semiconductor 243 Core platform modules...
Страница 244: ...MPC5606BK Microcontroller Reference Manual Rev 2 244 Freescale Semiconductor This page is intentionally left blank...
Страница 395: ...MPC5606BK Microcontroller Reference Manual Rev 2 Freescale Semiconductor 395 Communication modules...
Страница 396: ...MPC5606BK Microcontroller Reference Manual Rev 2 396 Freescale Semiconductor This page is intentionally left blank...
Страница 548: ...Chapter 24 LIN Controller LINFlexD MPC5606BK Microcontroller Reference Manual Rev 2 548 Freescale Semiconductor...
Страница 645: ...MPC5606BK Microcontroller Reference Manual Rev 2 Freescale Semiconductor 643 Timers...
Страница 646: ...MPC5606BK Microcontroller Reference Manual Rev 2 644 Freescale Semiconductor This page is intentionally left blank...
Страница 715: ...MPC5606BK Microcontroller Reference Manual Rev 2 Freescale Semiconductor 713 ADC system...
Страница 716: ...MPC5606BK Microcontroller Reference Manual Rev 2 714 Freescale Semiconductor This page is intentionally left blank...
Страница 787: ...MPC5606BK Microcontroller Reference Manual Rev 2 Freescale Semiconductor 787 Memory...
Страница 788: ...MPC5606BK Microcontroller Reference Manual Rev 2 788 Freescale Semiconductor This page is intentionally left blank...
Страница 893: ...MPC5606BK Microcontroller Reference Manual Rev 2 Freescale Semiconductor 893 Integrity...
Страница 894: ...MPC5606BK Microcontroller Reference Manual Rev 2 894 Freescale Semiconductor This page is intentionally left blank...
Страница 943: ...MPC5606BK Microcontroller Reference Manual Rev 2 Freescale Semiconductor 943 Debug...
Страница 944: ...MPC5606BK Microcontroller Reference Manual Rev 2 944 Freescale Semiconductor This page is intentionally left blank...