參數(shù)資料
型號: MP80C51C-30D
廠商: TEMIC SEMICONDUCTORS
元件分類: 微控制器/微處理器
英文描述: 8-BIT, MROM, 30 MHz, MICROCONTROLLER, PDIP40
文件頁數(shù): 96/170頁
文件大?。?/td> 4133K
代理商: MP80C51C-30D
31
ATtiny4/5/9/10 [DATASHEET]
8127F–AVR–02/2013
8.3.1
Procedure for Changing the Watchdog Timer Configuration
The sequence for changing configuration differs between the two safety levels, as follows:
8.3.1.1
Safety Level 1
In this mode, the Watchdog Timer is initially disabled, but can be enabled by writing the WDE bit to one without any
restriction. A special sequence is needed when disabling an enabled Watchdog Timer. To disable an enabled
Watchdog Timer, the following procedure must be followed:
1.
Write the signature for change enable of protected I/O registers to register CCP
2.
Within four instruction cycles, in the same operation, write WDE and WDP bits
8.3.1.2
Safety Level 2
In this mode, the Watchdog Timer is always enabled, and the WDE bit will always read as one. A protected change
is needed when changing the Watchdog Time-out period. To change the Watchdog Time-out, the following proce-
dure must be followed:
1.
Write the signature for change enable of protected I/O registers to register CCP
2.
Within four instruction cycles, write the WDP bit. The value written to WDE is irrelevant
8.3.2
Code Examples
The following code example shows how to turn off the WDT. The example assumes that interrupts are controlled
(e.g., by disabling interrupts globally) so that no interrupts will occur during execution of these functions.
Note:
Table 8-1.
WDT Configuration as a Function of the Fuse Settings of WDTON
WDTON
Safety
Level
WDT
Initial State
How to
Disable the WDT
How to
Change Time-out
Unprogrammed
1
Disabled
Protected change
sequence
No limitations
Programmed
2
Enabled
Always enabled
Protected change
sequence
Assembly Code Example
WDT_off:
wdr
; Clear WDRF in RSTFLR
in
r16, RSTFLR
andi
r16, ~(1<<WDRF)
out
RSTFLR, r16
; Write signature for change enable of protected I/O register
ldi
r16, 0xD8
out
CCP, r16
; Within four instruction cycles, turn off WDT
ldi
r16, (0<<WDE)
out
WDTCSR, r16
ret
相關(guān)PDF資料
PDF描述
MF180C31-12R 8-BIT, 12 MHz, MICROCONTROLLER, PQFP44
MS80C51C-20D 8-BIT, MROM, 20 MHz, MICROCONTROLLER, PQCC44
MT80C51-36D 8-BIT, MROM, 36 MHz, MICROCONTROLLER, PQFP44
MT80C51C-12D 8-BIT, MROM, 12 MHz, MICROCONTROLLER, PQFP44
MP80C51C-20D 8-BIT, MROM, 20 MHz, MICROCONTROLLER, PDIP40
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MP81 制造商:未知廠家 制造商全稱:未知廠家 功能描述:BRIDGE RECTIFIERS
MP810 制造商:GOOD-ARK 制造商全稱:GOOD-ARK Electronics 功能描述:SILICON BRIDGE RECTIFIERS
MP-810 制造商:JAMECO BENCHPRO 功能描述:4-Piece Plier/Cutter/Screwdrivers Set
MP8100 制造商:MPS 制造商全稱:Monolithic Power Systems 功能描述:Precision High-Side Current-Sense Amplifier
MP8100DS 制造商:MPS 制造商全稱:Monolithic Power Systems 功能描述:Precision High-Side Current-Sense Amplifier