- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄369945 > P90CE201AEB (NXP SEMICONDUCTORS) 16-bit microcontroller PDF資料下載
參數(shù)資料
| 型號： | P90CE201AEB |
| 廠商： | NXP SEMICONDUCTORS |
| 元件分類： | 微控制器/微處理器 |
| 英文描述： | 16-bit microcontroller |
| 中文描述： | 16-BIT, 24 MHz, MICROCONTROLLER, PQFP64 |
| 封裝： | PLASTIC, QFP-64 |
| 文件頁數(shù)： | 54/77頁 |
| 文件大?。?/td> | 235K |
| 代理商： | P90CE201AEB |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁當(dāng)前第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁
August 1993
54
Philips Semiconductors
Product specification
16-bit microcontroller
P90CE201
12 WATCHDOG TIMER
The P90CE201 contains a Watchdog Timer. Its purpose is
to reset the microcontroller, after a programmable time
interval, in the event of the microcontroller entering an
erroneous processor state. Erroneous processor states
can be caused by noise or RFI.
The Watchdog Timer consists of a 14-bit prescaler and an
8-bit timer (WDTIM). The prescaler is incremented by the
basic peripheral clock. WDTIM is incremented every
16384 cycles of the basic peripheral clock. It is the value
written to WDTIM that determines the Watchdog Timer
interval. If the timer interval is exceeded, the Watchdog
Timer overflows and the microcontroller is reset. In order
to prevent a timer overflow, the user program must reload
the Watchdog Timer within a time period shorter than the
programmed Watchdog Timer interval.
The Watchdog Timer is controlled by the Watchdog
Control Register (WDCON). WDCON can be read and
written to by software. After RESET, the Watchdog Timer
is disabled and WDCON contains A5H which clears both
the prescaler and WDTIM. The Watchdog Timer is
enabled by the first write operation to WDCON after
RESET. A running Watchdog Timer can only be disabled
by resetting the device.
WDTIM can be read on the fly but can only be written to if
WDCON has been loaded with 5AH. A successful write
operation to WDTIM also clears the prescaler and sets
WDCON to 00H in order to prevent further, unintentional,
write operations to WDTIM.
The Watchdog Timer interval (t) may be calculated as
WDTIM value
–
(
follows:
For example, if the basic peripheral clock frequency is 4
MHz, the Watchdog Timer interval will be within the range
4.1 ms to 1 second.
t
)
×
basic peripheral clock fre16384
=
Fig.39 Watchdog Timer.
handbook, full pagewidth
MLB253
INTERNAL BUS
write
WDTIM
PRESCALER
(14-BIT)
WDTIM
(8-BIT)
LOAD
CLEAREN
LOADEN
CLEAR
WDCON
INTERNAL BUS
CLEAR
BPCLK
to reset circuitry
from reset circuitry
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| P9217 | PbS photoconductive detector |
| P930 | CdS photoconductive cell |
| PA025XSB | This technical specification applies to 2.5inch color TFT-LCD panel. |
| PA025XSC | This technical specification applies to 2.5inch color TFT-LCD panel. |
| PA035XUJ | This technical specification applies to 3.5inch color TFT-LCD panel. |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| P90CL301 | 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Low voltage 16-bit microcontroller |
| P90CL301BFH | 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Low voltage 16-bit microcontroller |
| P-90-F | 制造商:Hozan Tool Industrial Co Ltd 功能描述: |
| P90PCT101PC | 制造商:PERFORMANCE/ 功能描述:90PCT101PC |
| P-910 | 制造商:Hozan Tool Industrial Co Ltd 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。