- 您现在的位置：买卖IC网 > PDF目录372305 > ST62T94B8 Telecommunication IC PDF资料下载
参数资料
| 型号： | ST62T94B8 |
| 英文描述： | Telecommunication IC |
| 中文描述： | 通信集成电路 |
| 文件页数： | 24/82页 |
| 文件大小： | 870K |
| 代理商： | ST62T94B8 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页当前第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页第65页第66页第67页第68页第69页第70页第71页第72页第73页第74页第75页第76页第77页第78页第79页第80页第81页第82页
24/82
ST62T18C/E18C
3.3 DIGITAL WATCHDOG
The digital Watchdog consists of a reloadable
downcounter timer which can be used to provide
controlled recovery from software upsets.
The Watchdog circuit generates a Reset when the
downcounter reaches zero. User software can
prevent this reset by reloading the counter, and
should therefore be written so that the counter is
regularly reloaded while the user program runs
correctly. In the event of a software mishap (usual-
ly caused by externally generated interference),
the user program will no longer behave in its usual
fashion and the timer register will thus not be re-
loaded periodically. Consequently the timer will
decrement down to 00h and reset the MCU. In or-
der to maximise the effectiveness of the Watchdog
function, user software must be written with this
concept in mind.
Watchdog behaviour is governed by two options,
known as “WATCHDOG ACTIVATION” (i.e.
HARDWARE or SOFTWARE) and “EXTERNAL
STOP MODE CONTROL” (see
Table 7
).
In the SOFTWARE option, the Watchdog is disa-
bled until bit C of the DWDR register has been set.
When the Watchdog is disabled, low power Stop
mode is available. Once activated, the Watchdog
cannot be disabled, except by resetting the MCU.
In the HARDWARE option, the Watchdog is per-
manently enabled. Since the oscillator will run con-
tinuously, low power mode is not available. The
STOP instruction is interpreted as a WAIT instruc-
tion, and the Watchdog continues to countdown.
However, when the EXTERNAL STOP MODE
CONTROL option has been selected low power
consumption may be achieved in Stop Mode.
Execution of the STOP instruction is then gov-
erned by a secondary function associated with the
NMI pin. If a STOP instruction is encountered
when the NMI pin is low, it is interpreted as WAIT,
as described above. If, however, the STOP in-
struction is encountered when the NMI pin is high,
the Watchdog counter is frozen and the CPU en-
ters STOP mode.
When the MCU exits STOP mode (i.e. when an in-
terrupt is generated), the Watchdog resumes its
activity.
Table 7. Recommended Option Choices
Functions Required
Stop Mode & Watchdog
Stop Mode
Watchdog
Recommended Options
“EXTERNAL STOP MODE” & “HARDWARE WATCHDOG”
“SOFTWARE WATCHDOG”
“HARDWARE WATCHDOG”
24
相关PDF资料 |
PDF描述 |
|---|---|
| ST62T94M8 | Telecommunication IC |
| ST6228C | 8-BIT MICROCONTROLLER ( MCU ) WITH OTP. ROM. FASTR A/D CONVERTER. 8-BIT AUTO-RELOAD TIMER. UART. OSG. SAFE RESET AND 28 PINS |
| ST62E28CF1 | 8-BIT MICROCONTROLLER ( MCU ) WITH OTP. ROM. FASTR A/D CONVERTER. 8-BIT AUTO-RELOAD TIMER. UART. OSG. SAFE RESET AND 28 PINS |
| ST62P28CB1 | 8-BIT MICROCONTROLLER ( MCU ) WITH OTP. ROM. FASTR A/D CONVERTER. 8-BIT AUTO-RELOAD TIMER. UART. OSG. SAFE RESET AND 28 PINS |
| ST62P28CB3 | 8-BIT MICROCONTROLLER ( MCU ) WITH OTP. ROM. FASTR A/D CONVERTER. 8-BIT AUTO-RELOAD TIMER. UART. OSG. SAFE RESET AND 28 PINS |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ST63/69/23 | 制造商:Block 功能描述:Control panel transformer, 63VA, 230V |
| ST6-30 | 制造商:SUPERWORLD 制造商全称:Superworld Electronics 功能描述:POWER TRANSFORMER |
| ST630/69/23 | 制造商:Block USA Inc. 功能描述:Control panel transformer, 630VA, 230V |
| ST6306 | 制造商:未知厂家 制造商全称:未知厂家 功能描述:8-Bit Microcontroller |
| ST6307 | 制造商:未知厂家 制造商全称:未知厂家 功能描述:8-Bit Microcontroller |
发布紧急采购，3分钟左右您将得到回复。