參數(shù)資料
型號(hào): pic12ce674
廠商: Microchip Technology Inc.
英文描述: 8-Pin, 8-Bit CMOS Microcontroller with A/D Converter(具A/D轉(zhuǎn)換器和EEPROM數(shù)據(jù)存儲(chǔ)器的8位微控制器)
中文描述: 8引腳,8位CMOS微控制器與A / D轉(zhuǎn)換器(具的A / D轉(zhuǎn)換器和EEPROM的數(shù)據(jù)存儲(chǔ)器的8位微控制器)
文件頁(yè)數(shù): 57/112頁(yè)
文件大?。?/td> 1205K
代理商: PIC12CE674
1998 Microchip Technology Inc.
Preliminary
DS40181A-page 57
PIC12CE67X
9.7
The Watchdog Timer is a free running on-chip RC oscil-
lator which does not require any external components.
This RC oscillator is separate from the RC oscillator 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. During
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
configuration
(Section 9.1).
Watchdog Timer (WDT)
bit WDTE
9.7.1
WDT PERIOD
The WDT has a nominal time-out period of 18 ms, (with
no prescaler). The time-out periods vary with tempera-
ture, V
DD
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
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 early and generating a premature
device RESET condition.
The TO bit in the STATUS register will be cleared upon
a Watchdog Timer time-out.
9.7.2
WDT PROGRAMMING CONSIDERATIONS
It should also be taken into account that under worst
case conditions (V
DD
= Min., Temperature = Max., and
max. WDT prescaler) it may take several seconds
before a WDT time-out occurs.
Note:
When the prescaler is assigned to the
WDT, always execute a
CLRWDT
instruction
before changing the prescale value, other-
wise a WDT reset may occur.
FIGURE 9-16: WATCHDOG TIMER BLOCK DIAGRAM
FIGURE 9-17: SUMMARY OF WATCHDOG TIMER REGISTERS
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
2007h
Config. bits
(1)
OPTION
MCLRE
CP1
CP0
PWRTE
WDTE
FOSC2
FOSC1
FOSC0
81h
Legend: Shaded cells are not used by the Watchdog Timer.
Note 1: See Figure 9-1 for operation of these bits. Not all CP0 and CP1 bits are shown.
GPPU
INTEDG
T0CS
T0SE
PSA
PS2
PS1
PS0
From TMR0 Clock Source
(Figure 7-5)
To TMR0 (Figure 7-5)
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
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PIC12CE674/JW 功能描述:8位微控制器 -MCU 3.5KB 128 RAM 6 I/O 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(shí)鐘頻率:50 MHz 程序存儲(chǔ)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
PIC12CE674-04/JM 制造商:MICROCHIP 制造商全稱(chēng):Microchip Technology 功能描述:8-Pin, 8-Bit CMOS Microcontroller with A/D Converter
PIC12CE674-04/JW 制造商:MICROCHIP 制造商全稱(chēng):Microchip Technology 功能描述:8-Pin, 8-Bit CMOS Microcontroller with A/D Converter and EEPROM Data Memory
PIC12CE674-04/P 功能描述:8位微控制器 -MCU 3.5KB 128 RAM 6 I/O 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(shí)鐘頻率:50 MHz 程序存儲(chǔ)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
PIC12CE674-04/P 制造商:Microchip Technology Inc 功能描述:IC 8BIT CMOS MCU 12CE674 DIP8