Section 11 Watchdog Timer (WDT)
Rev. 5.00 May 29, 2006 page 315 of 698
REJ09B0146-0500
Section 11 Watchdog Timer (WDT)
The WDT is a single-channel timer that counts the clock settling time and is used when clearing
software standby mode and temporary standbys, such as frequency changes. It can also be used as
an ordinary watchdog timer or interval timer.
Figure 11.1 shows a block diagram of the WDT.
WTCSR
Standby
control
Bus interface
WTCNT
Divider
Clock selector
Clock
Standby
mode
Peripheral
clock
Standby
cancellation
Reset
control
Clock selection
WDT
Overflow
Internal
reset
request
Interrupt
control
Interrupt
request
Legend:
WTCSR: Watchdog timer control/status register
WTCNT: Watchdog timer counter
Figure 11.1 Block Diagram of the WDT
11.1
Feature
The WDT has the following features:
•
Can be used to ensure the clock setting time: Use the WDT to cancel software standby mode
and the temporary standbys that occur when the clock frequency is changed.
•
Can switch between watchdog timer mode and interval timer mode.
•
Generates internal resets in watchdog timer mode: Internal resets occur after counter overflow.
Selection of power-on reset or manual reset.
•
Generates interrupts in interval timer mode: Internal timer interrupts occur after counter
overflow.
•
Selection of eight counter input clocks. Eight clocks (
×
1 to
×
1/4096) can be obtained by
dividing the peripheral clock.
Содержание SH7706 Series
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Страница 160: ...Section 5 Cache Rev 5 00 May 29 2006 page 112 of 698 REJ09B0146 0500 ...
Страница 370: ...Section 11 Watchdog Timer WDT Rev 5 00 May 29 2006 page 322 of 698 REJ09B0146 0500 ...
Страница 532: ...Section 16 Serial Communication Interface with FIFO SCIF Rev 5 00 May 29 2006 page 484 of 698 REJ09B0146 0500 ...
Страница 554: ...Section 17 Pin Function Controller PFC Rev 5 00 May 29 2006 page 506 of 698 REJ09B0146 0500 ...
Страница 576: ...Section 18 I O Ports Rev 5 00 May 29 2006 page 528 of 698 REJ09B0146 0500 ...
Страница 614: ...Section 21 User Debugging Interface H UDI Rev 5 00 May 29 2006 page 566 of 698 REJ09B0146 0500 ...
Страница 746: ...Index Rev 5 00 May 29 2006 page 698 of 698 REJ09B0146 0500 ...
Страница 749: ...SH7706 Group Hardware Manual ...