- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄363898 > W78E51C (WINBOND ELECTRONICS CORP) 8 bit micocontroller PDF資料下載
參數(shù)資料
| 型號(hào)： | W78E51C |
| 廠商： | WINBOND ELECTRONICS CORP |
| 英文描述： | 8 bit micocontroller |
| 中文描述： | 8位micocontroller |
| 文件頁數(shù)： | 9/23頁 |
| 文件大?。?/td> | 302K |
| 代理商： | W78E51C |
W78E51C
Publication Release Date: April 20, 2005
- 9 -
Revision A2
6.3 Watchdog Timer
The Watchdog timer is a free-running timer which can be programmed by the user to serve as a
system monitor, a time-base generator or an event timer. It is basically a set of dividers that divide the
system clock. The divider output is selectable and determines the time-out interval. When the time-out
occurs a system reset can also be caused if it is enabled. The main use of the Watchdog timer is as a
system monitor. This is important in real-time control applications. In case of power glitches or electro-
magnetic interference, the processor may begin to execute errant code. If this is left unchecked the
entire system may crash. The watchdog time-out selection will result in different time-out values
depending on the clock speed. The Watchdog timer will de disabled on reset. In general, software
should restart the Watchdog timer to put it into a known state. The control bits that support the
Watchdog timer are discussed below.
Watchdog Timer Control Register
Bit:
7
6
5
4
-
3
-
2
1
0
ENW
CLRW
WIDL
PS2
PS1
PS0
Mnemonic: WDTC Address: 8FH
ENW : Enable watch-dog if set.
CLRW: Clear watch-dog timer and prescaler if set. This flag will be cleared automatically
WIDL : If this bit is set, watch-dog is enabled under IDLE mode. If cleared, watch-dog is disabled
under IDLE mode. Default is cleared.
PS2, PS1, PS0: Watch-dog prescaler timer select. Prescaler is selected when set PS2~0 as follows:
PS2 PS1 PS0
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
PRESCALER SELECT
2
4
8
16
32
64
128
256
The time-out period is obtained using the following equation:
1
OSC
2
PRESCALER 1000 12 mS
14
×
×
Before Watchdog time-out occurs, the program must clear the 14-bit timer by writing 1 to WDTC.6
(CLRW). After 1 is written to this bit, the 14-bit timer, prescaler and this bit will be reset on the next
instruction cycle. The Watchdog timer is cleared on reset.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| W78E51 | 8-BIT MTP Monitor Microcontroller(多次可編程的8位的監(jiān)視微控制器) |
| W78E52 | 8-BIT MTP Monitor Microcontroller(多次可編程的8位的監(jiān)視微控制器) |
| W78E56B | 8-BIT Microcontroller(8位的微控制器) |
| W78E516BP-24 | 8-BIT MICROCONTROLLER |
| W78E516BP-40 | 8-BIT MICROCONTROLLER |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| W78E51C_06 | 制造商:WINBOND 制造商全稱:Winbond 功能描述:8-BIT MICROCONTROLLER |
| W78E51P-16 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-Bit Microcontroller |
| W78E51P-24 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-Bit Microcontroller |
| W78E51P-33 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-Bit Microcontroller |
| W78E51P-40 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-Bit Microcontroller |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。