- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄363899 > W78IE54P (WINBOND ELECTRONICS CORP) 8-BIT MTP MICROCONTROLLER PDF資料下載
參數(shù)資料
| 型號： | W78IE54P |
| 廠商： | WINBOND ELECTRONICS CORP |
| 元件分類： | 微控制器/微處理器 |
| 英文描述： | 8-BIT MTP MICROCONTROLLER |
| 中文描述： | 8-BIT, FLASH, 20 MHz, MICROCONTROLLER, PQCC44 |
| 封裝： | PLASTIC, LCC-44 |
| 文件頁數(shù)： | 7/21頁 |
| 文件大小： | 211K |
| 代理商： | W78IE54P |
Preliminary W78IE54
Publication Release Date: August 1999
- 7 -
Revision A1
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 1 0
0 0 1
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 |
|---|---|
| W78IRD2 | 8-BIT MICROCONTROLLER |
| W78IRD2A | 8-BIT MICROCONTROLLER |
| W78L052A | 8-BIT MICROCONTROLLER |
| W78L058 | 8-BIT MICROCONTROLLER |
| W78L058A | 8-BIT MICROCONTROLLER |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| W78IRD2 | 制造商:WINBOND 制造商全稱:Winbond 功能描述:8-BIT MICROCONTROLLER |
| W78IRD2A | 制造商:WINBOND 制造商全稱:Winbond 功能描述:8-BIT MICROCONTROLLER |
| W78IRD2A25DL | 功能描述:IC MCU 8-BIT 64K FLASH 40-DIP RoHS:是 類別:集成電路 (IC) >> 嵌入式 - 微控制器， 系列:W78 標(biāo)準包裝:300 系列:78K0R/Ix3 核心處理器:78K/0R 芯體尺寸:16-位 速度:40MHz 連通性:3 線 SIO，I²C，LIN，UART/USART 外圍設(shè)備:DMA，LVD，POR，PWM，WDT 輸入/輸出數(shù):27 程序存儲器容量:16KB（16K x 8） 程序存儲器類型:閃存 EEPROM 大小:- RAM 容量:1K x 8 電壓 - 電源 (Vcc/Vdd):2.7 V ~ 5.5 V 數(shù)據(jù)轉(zhuǎn)換器:A/D 8x10b 振蕩器型:內(nèi)部 工作溫度:-40°C ~ 85°C 封裝/外殼:38-SSOP 包裝:托盤 |
| W78IRD2A25PL | 功能描述:IC MCU 8-BIT 64K FLASH 44-PLCC RoHS:是 類別:集成電路 (IC) >> 嵌入式 - 微控制器， 系列:W78 標(biāo)準包裝:300 系列:78K0R/Ix3 核心處理器:78K/0R 芯體尺寸:16-位 速度:40MHz 連通性:3 線 SIO，I²C，LIN，UART/USART 外圍設(shè)備:DMA，LVD，POR，PWM，WDT 輸入/輸出數(shù):27 程序存儲器容量:16KB（16K x 8） 程序存儲器類型:閃存 EEPROM 大小:- RAM 容量:1K x 8 電壓 - 電源 (Vcc/Vdd):2.7 V ~ 5.5 V 數(shù)據(jù)轉(zhuǎn)換器:A/D 8x10b 振蕩器型:內(nèi)部 工作溫度:-40°C ~ 85°C 封裝/外殼:38-SSOP 包裝:托盤 |
| W78J_1TG WAF | 制造商:Fairchild Semiconductor Corporation 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。