- 您現(xiàn)在的位置：買(mǎi)賣(mài)IC網(wǎng) > PDF目錄363900 > W79E201A16FN (WINBOND ELECTRONICS CORP) 8-BIT MICROCONTROLLER PDF資料下載
參數(shù)資料
| 型號(hào)： | W79E201A16FN |
| 廠商： | WINBOND ELECTRONICS CORP |
| 元件分類(lèi)： | 微控制器/微處理器 |
| 英文描述： | 8-BIT MICROCONTROLLER |
| 中文描述： | 8-BIT, FLASH, 16 MHz, MICROCONTROLLER, PQFP44 |
| 封裝： | ROHS COMPLIANT, QFP-44 |
| 文件頁(yè)數(shù)： | 48/87頁(yè) |
| 文件大小： | 818K |
| 代理商： | W79E201A16FN |
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)第19頁(yè)第20頁(yè)第21頁(yè)第22頁(yè)第23頁(yè)第24頁(yè)第25頁(yè)第26頁(yè)第27頁(yè)第28頁(yè)第29頁(yè)第30頁(yè)第31頁(yè)第32頁(yè)第33頁(yè)第34頁(yè)第35頁(yè)第36頁(yè)第37頁(yè)第38頁(yè)第39頁(yè)第40頁(yè)第41頁(yè)第42頁(yè)第43頁(yè)第44頁(yè)第45頁(yè)第46頁(yè)第47頁(yè)當(dāng)前第48頁(yè)第49頁(yè)第50頁(yè)第51頁(yè)第52頁(yè)第53頁(yè)第54頁(yè)第55頁(yè)第56頁(yè)第57頁(yè)第58頁(yè)第59頁(yè)第60頁(yè)第61頁(yè)第62頁(yè)第63頁(yè)第64頁(yè)第65頁(yè)第66頁(yè)第67頁(yè)第68頁(yè)第69頁(yè)第70頁(yè)第71頁(yè)第72頁(yè)第73頁(yè)第74頁(yè)第75頁(yè)第76頁(yè)第77頁(yè)第78頁(yè)第79頁(yè)第80頁(yè)第81頁(yè)第82頁(yè)第83頁(yè)第84頁(yè)第85頁(yè)第86頁(yè)第87頁(yè)
W79E201
- 48 -
12. 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 flag is set, which can cause an interrupt if enabled, and a system reset can also be caused if
it is enabled. The interrupt will occur if the individual interrupt enable and the global enable are set.
The interrupt and reset functions are independent of each other and may be used separately or
together depending on the user’s software.
16
WD1,WD0
00
01
10
11
Interrupt
Reset
Enable Watchdog timer reset
EWT(WDCON.1)
Reset Watchdog
RWT(WDCON.0)
0
17
19
20
22
23
25
Time-out
WDIF
WTRF
512 clock
delay
EWDI(EIE.4)
XT
Watchdog Timer
The Watchdog timer should first be restarted by using RWT. This ensures that the timer starts from a
known state. The RWT bit is used to restart the watchdog timer. This bit is self clearing, i.e. after
writing a 1 to this bit the software will automatically clear it. The watchdog timer will now count clock
cycles. The time-out interval is selected by the two bits WD1 and WD0 (CKCON.7 and CKCON.6).
When the selected time-out occurs, the Watchdog interrupt flag WDIF (WDCON.3) is set. After the
time-out has occurred, the watchdog timer waits for an additional 512 clock cycles. If the Watchdog
Reset EWT (WDCON.1) is enabled, then 512 clocks after the time-out, if there is no RWT, a system
reset due to Watchdog timer will occur. This will last for two machine cycles, and the Watchdog timer
reset flag WTRF (WDCON.2) will be set. This indicates to the software that the watchdog was the
cause of the reset.
When used as a simple timer, the reset and interrupt functions are disabled. The timer will set the
WDIF flag each time the timer completes the selected time interval. The WDIF flag is polled to detect
a time-out and the RWT allows software to restart the timer. The Watchdog timer can also be used as
a very long timer. The interrupt feature is enabled in this case. Every time the time-out occurs an
interrupt will occur if the global interrupt enable EA is set.
The main use of the Watchdog timer is as a system monitor. This is important in real-time control
applications. In case of some power glitches or electro-magnetic interference, the processor may
begin to execute errant code. If this is left unchecked the entire system may crash. Using the
watchdog timer interrupt during software development will allow the user to select ideal watchdog
reset locations. The code is first written without the watchdog interrupt or reset. Then the watchdog
interrupt is enabled to identify code locations where interrupt occurs. The user can now insert
instructions to reset the watchdog timer which will allow the code to run without any watchdog timer
interrupts. Now the watchdog timer reset is enabled and the watchdog interrupt may be disabled. If
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| W79E201A16LN | 8-BIT MICROCONTROLLER |
| W79E201A16PN | 8-BIT MICROCONTROLLER |
| W79E217A | 8-BIT MICROCONTROLLER |
| W79E217AFG | 8-BIT MICROCONTROLLER |
| W79E225A | 8-BIT MICROCONTROLLER |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| W79E201A16LN | 制造商:WINBOND 制造商全稱(chēng):Winbond 功能描述:8-BIT MICROCONTROLLER |
| W79E201A16PL | 功能描述:IC MCU 8-BIT 16K FLASH 44-PLCC RoHS:是 類(lèi)別:集成電路 (IC) >> 嵌入式 - 微控制器， 系列:W79 標(biāo)準(zhǔn)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(xiàn) 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(chǔ)器容量:16KB（16K x 8） 程序存儲(chǔ)器類(lèi)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(pán) |
| W79E201A16PN | 制造商:WINBOND 制造商全稱(chēng):Winbond 功能描述:8-BIT MICROCONTROLLER |
| W79E2051 | 制造商:WINBOND 制造商全稱(chēng):Winbond 功能描述: |
| W79E2051AKG | 制造商:Winbond Electronics Corp 功能描述:8 BIT MCU 制造商:Nuvoton Technology Corp 功能描述:IC MCU 2KB FLASH 20PDIP |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。