參數(shù)資料
型號: AT90S8535-8JI
廠商: Atmel
文件頁數(shù): 90/127頁
文件大?。?/td> 0K
描述: IC MCU 8K 8MHZ A/D IT 44PLCC
標(biāo)準(zhǔn)包裝: 27
系列: AVR® 90S
核心處理器: AVR
芯體尺寸: 8-位
速度: 8MHz
連通性: SPI,UART/USART
外圍設(shè)備: 欠壓檢測/復(fù)位,POR,PWM,WDT
輸入/輸出數(shù): 32
程序存儲器容量: 8KB(4K x 16)
程序存儲器類型: 閃存
EEPROM 大?。?/td> 512 x 8
RAM 容量: 512 x 8
電壓 - 電源 (Vcc/Vdd): 4 V ~ 6 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: 44-LCC(J 形引線)
包裝: 管件
1997 Microchip Technology Inc.
DS30272A-page 65
PIC16C71X
8.7
Watchdog Timer (WDT)
The Watchdog Timer is as a free running on-chip RC
oscillator which does not require any external compo-
nents. This RC oscillator is separate from the RC oscil-
lator of the OSC1/CLKIN pin. That means that the WDT
will run, even if the clock on the OSC1/CLKIN and
OSC2/CLKOUT pins of the device has been stopped,
for example, by execution of a SLEEP instruction. Dur-
ing normal operation, a WDT time-out generates a
device RESET (Watchdog Timer Reset). If the device is
in SLEEP mode, a WDT time-out causes the device to
wake-up and continue with normal operation (Watch-
dog Timer Wake-up). The WDT can be permanently
disabled
by
clearing
conguration
bit
WDTE
8.7.1
WDT PERIOD
The WDT has a nominal time-out period of 18 ms, (with
no prescaler). The time-out periods vary with tempera-
ture, VDD and process variations from part to part (see
DC specs). If longer time-out periods are desired, a
prescaler with a division ratio of up to 1:128 can be
Applicable Devices
710 71 711 715
assigned to the WDT under software control by writing
to the OPTION register. Thus, time-out periods up to
2.3 seconds can be realized.
The CLRWDT and SLEEP instructions clear the WDT and
the postscaler, if assigned to the WDT, and prevent it
from timing out and generating a device RESET condi-
tion.
The TO bit in the STATUS register will be cleared upon
a Watchdog Timer time-out.
8.7.2
WDT PROGRAMMING CONSIDERATIONS
It should also be taken into account that under worst
case conditions (VDD = Min., Temperature = Max., and
max. WDT prescaler) it may take several seconds
before a WDT time-out occurs.
Note:
When a CLRWDT instruction is executed
and the prescaler is assigned to the WDT,
the prescaler count will be cleared, but the
prescaler assignment is not changed.
FIGURE 8-20: WATCHDOG TIMER BLOCK DIAGRAM
FIGURE 8-21: SUMMARY OF WATCHDOG TIMER REGISTERS
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
2007h
Cong. bits
(1)
BODEN(1)
CP1
CP0
PWRTE(1)
WDTE
FOSC1
FOSC0
81h,181h
OPTION
RBPU
INTEDG
T0CS
T0SE
PSA
PS2
PS1
PS0
Legend: Shaded cells are not used by the Watchdog Timer.
Note 1: See Figure 8-1, Figure 8-2 and Figure 8-3 for operation of these bits.
From TMR0 Clock Source
To TMR0 (Figure 6-6)
Postscaler
WDT Timer
WDT
Enable Bit
0
1
M
U
X
PSA
8 - to - 1 MUX
PS2:PS0
0
1
MUX
PSA
WDT
Time-out
Note: PSA and PS2:PS0 are bits in the OPTION register.
8
相關(guān)PDF資料
PDF描述
PIC16F870-I/SO IC MCU FLASH 2KX14 EE 28SOIC
AT90S8515-8PC IC MCU 8K FLSH 8MHZ 40DIP
PIC18LF45J50-I/PT IC PIC MCU FLASH 32K 2V 44-TQFP
PIC18LF1230-I/P IC PIC MCU FLASH 2KX16 18DIP
PIC18F45J50-I/PT IC PIC MCU FLASH 32K 2V 44-TQFP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AT90S8535-8PC 功能描述:8位微控制器 -MCU 8K Flash 5V RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
AT90S8535-8PI 功能描述:8位微控制器 -MCU 8K Flash 5V RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
AT90SA7-MLTU 功能描述:程序設(shè)計器 - 基于通用和內(nèi)存 ASICS RoHS:否 制造商:Xeltek 產(chǎn)品:Universal Device Programmers 工具用于評估:EPROM, Parallel/Serial EEPROM, FPGA, PROM, Flash, BPROM, MCUs, PLD Devices 接口類型:Parallel, USB 工作電源電壓:90 VAC to 250 VAC
AT90SC12036RU 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:Secure Microcontroller for Smart Cards
AT90SC128112RU 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:Secure Microcontroller for Smart Cards