參數(shù)資料
型號(hào)： UPD17147CT
廠商： NEC Corp.
英文描述： SMALL, GENERAL-PURPOSE 4-BIT SINGLE-CHIP MICROCONTROLLERS
中文描述： 小，通用4位單晶片微控制器
文件頁數(shù)： 43/102頁
文件大?。?/td> 408K
代理商： UPD17147CT
43
μ
PD17145(A1), 17147(A1), 17149(A1)
13.3 Watchdog Timer Function
The basic interval timer can also be used as a watchdog timer that detects a program runaway.
13.3.1 Function of watchdog timer
The watchdog timer is a counter that generates a reset signal at fixed time intervals. By inhibiting generation
of this reset signal by program, the system can be reset (started from address 0000H) if the system becomes
runaway due to external noise (if the watchdog timer is not reset within specific time).
This function allows the program to escape from the runaway status because a reset signal is generated at
fixed time intervals even when the program jumps to an unexpected routine and enters an indefinite loop due
to external noise.
13.3.2 Operation of watchdog timer
When WDTEN is set to 1, the 1-bit divider is enabled to operate, and the basic interval timer starts operating
as an 8-bit watchdog timer.
Once the watchdog timer has been started, it cannot be stopped until the device is reset and WDTEN is
cleared to 0.
Reset effected by the watchdog timer can be inhibited in the following two ways:
(1)
(2)
Repeatedly set WDTRES in the program.
Repeatedly set BTMRES in the program.
In the case of (1), WDTRES must be set while the count value of the watchdog timer is 8 to 191 (before it
reaches 192). Therefore, program so that “SET1 WDTRES” is executed at least once in a cycle shorter than
that in which the watchdog timer counts 184.
In the case of (2), BTMRES must be set before the basic interval timer (BTM) counts 128. Therefore, program
so that “SET1 BTMRES” is executed at least once in a cycle shorter than that in which BTM counts 128. In this
case, however, interrupts cannot be processed with BTM.
Caution
BTM is not reset even if WDTEN is set. Therefore, before setting WDTEN first, be sure to
set BTMRES to reset BTM.
Example
SET1 BTMRES
SET2 WDTEN, WDTRES
…
…
相關(guān)PDF資料
PDF描述
UPD17147CTA1 SMALL, GENERAL-PURPOSE 4-BIT SINGLE-CHIP MICROCONTROLLERS
UPD17149 SMALL, GENERAL-PURPOSE 4-BIT SINGLE-CHIP MICROCONTROLLERS
UPD17149CT SMALL, GENERAL-PURPOSE 4-BIT SINGLE-CHIP MICROCONTROLLERS
UPD17147GT SMALL, GENERAL-PURPOSE 4-BIT SINGLE-CHIP MICROCONTROLLERS
UPD17147GTA1 SMALL, GENERAL-PURPOSE 4-BIT SINGLE-CHIP MICROCONTROLLERS
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
UPD17147CTA1 制造商:NEC 制造商全稱:NEC 功能描述:SMALL, GENERAL-PURPOSE 4-BIT SINGLE-CHIP MICROCONTROLLERS
UPD17147GT 制造商:NEC 制造商全稱:NEC 功能描述:SMALL, GENERAL-PURPOSE 4-BIT SINGLE-CHIP MICROCONTROLLERS
UPD17147GTA1 制造商:NEC 制造商全稱:NEC 功能描述:SMALL, GENERAL-PURPOSE 4-BIT SINGLE-CHIP MICROCONTROLLERS
UPD17149 制造商:NEC 制造商全稱:NEC 功能描述:SMALL, GENERAL-PURPOSE 4-BIT SINGLE-CHIP MICROCONTROLLERS
UPD17149CT 制造商:NEC 制造商全稱:NEC 功能描述:SMALL, GENERAL-PURPOSE 4-BIT SINGLE-CHIP MICROCONTROLLERS
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。

采購需求

(若只采購一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購

我的聯(lián)系方式

*
*
*