- 您現(xiàn)在的位置：買(mǎi)賣(mài)IC網(wǎng) > PDF目錄45035 > M37542F8VGP 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PQFP32 PDF資料下載
參數(shù)資料
| 型號(hào)： | M37542F8VGP |
| 元件分類(lèi)： | 微控制器/微處理器 |
| 英文描述： | 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PQFP32 |
| 封裝： | 7 X 7 MM, 0.80 MM PITCH, PLASTIC, LQFP-32 |
| 文件頁(yè)數(shù)： | 109/139頁(yè) |
| 文件大?。?/td> | 1448K |
| 代理商： | M37542F8VGP |
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)第19頁(yè)第20頁(yè)第21頁(yè)第22頁(yè)第23頁(yè)第24頁(yè)第25頁(yè)第26頁(yè)第27頁(yè)第28頁(yè)第29頁(yè)第30頁(yè)第31頁(yè)第32頁(yè)第33頁(yè)第34頁(yè)第35頁(yè)第36頁(yè)第37頁(yè)第38頁(yè)第39頁(yè)第40頁(yè)第41頁(yè)第42頁(yè)第43頁(yè)第44頁(yè)第45頁(yè)第46頁(yè)第47頁(yè)第48頁(yè)第49頁(yè)第50頁(yè)第51頁(yè)第52頁(yè)第53頁(yè)第54頁(yè)第55頁(yè)第56頁(yè)第57頁(yè)第58頁(yè)第59頁(yè)第60頁(yè)第61頁(yè)第62頁(yè)第63頁(yè)第64頁(yè)第65頁(yè)第66頁(yè)第67頁(yè)第68頁(yè)第69頁(yè)第70頁(yè)第71頁(yè)第72頁(yè)第73頁(yè)第74頁(yè)第75頁(yè)第76頁(yè)第77頁(yè)第78頁(yè)第79頁(yè)第80頁(yè)第81頁(yè)第82頁(yè)第83頁(yè)第84頁(yè)第85頁(yè)第86頁(yè)第87頁(yè)第88頁(yè)第89頁(yè)第90頁(yè)第91頁(yè)第92頁(yè)第93頁(yè)第94頁(yè)第95頁(yè)第96頁(yè)第97頁(yè)第98頁(yè)第99頁(yè)第100頁(yè)第101頁(yè)第102頁(yè)第103頁(yè)第104頁(yè)第105頁(yè)第106頁(yè)第107頁(yè)第108頁(yè)當(dāng)前第109頁(yè)第110頁(yè)第111頁(yè)第112頁(yè)第113頁(yè)第114頁(yè)第115頁(yè)第116頁(yè)第117頁(yè)第118頁(yè)第119頁(yè)第120頁(yè)第121頁(yè)第122頁(yè)第123頁(yè)第124頁(yè)第125頁(yè)第126頁(yè)第127頁(yè)第128頁(yè)第129頁(yè)第130頁(yè)第131頁(yè)第132頁(yè)第133頁(yè)第134頁(yè)第135頁(yè)第136頁(yè)第137頁(yè)第138頁(yè)第139頁(yè)
7542 Group
Rev.3.02
Oct 31, 2006
Page 71 of 134
REJ03B0006-0302
5. Setup for I/O ports
Setup I/O ports using hardware and software as follows:
<Hardware>
Connect a resistor of 100 or more to an I/O port in series.
<Software>
As for an input port, read data several times by a program for
checking whether input levels are equal or not.
As for an output port, since the output data may reverse because
of noise, rewrite data to its port latch at fixed periods.
Rewrite data to direction registers and pull-up control registers at
fixed periods.
Fig. 92 Setup for I/O ports
6. Providing of watchdog timer function by software
If a microcomputer runs away because of noise or others, it can
be detected by a software watchdog timer and the microcomputer
can be reset to normal operation. This is equal to or more effective
than program runaway detection by a hardware watchdog timer.
The following shows an example of a watchdog timer provided by
software.
In the following example, to reset a microcomputer to normal op-
eration, the main routine detects errors of the interrupt processing
routine and the interrupt processing routine detects errors of the
main routine.
This example assumes that interrupt processing is repeated mul-
tiple times in a single main routine processing.
Fig. 93 Watchdog timer by software
<The main routine>
Assigns a single byte of RAM to a software watchdog timer
(SWDT) and writes the initial value N in the SWDT once at each
execution of the main routine. The initial value N should satisfy
the following condition:
N+1 ≥ (Counts of interrupt processing executed in each main
routine)
As the main routine execution cycle may change because of an
interrupt processing or others, the initial value N should have a
margin.
Watches the operation of the interrupt processing routine by
comparing the SWDT contents with counts of interrupt process-
ing after the initial value N has been set.
Detects that the interrupt processing routine has failed and de-
termines to branch to the program initialization routine for
recovery processing in the following case:
If the SWDT contents do not change after interrupt processing.
<The interrupt processing routine>
Decrements the SWDT contents by 1 at each interrupt process-
ing.
Determines that the main routine operates normally when the
SWDT contents are reset to the initial value N at almost fixed
cycles (at the fixed interrupt processing count).
Detects that the main routine has failed and determines to
branch to the program initialization routine for recovery process-
ing in the following case:
If the SWDT contents are not initialized to the initial value N but
continued to decrement and if they reach 0 or less.
Main routine
(SWDT)← N
CLI
Main processing
(SWDT)
Interrupt processing
routine errors
N
Interrupt processing routine
(SWDT) ← (SWDT)—1
Interrupt processing
(SWDT)
Main routine
errors
>0
≤0
RTI
Return
=N?
≤0?
≠N
Direction register
Port latch
Data bus
I/O port
pins
Noise
N.G.
O.K.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| M37542M2V-XXXGP | 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PQFP32 |
| M37542M2V-XXXGP | 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PQFP32 |
| M37542M2-XXXSP | 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PDIP32 |
| M37542F8SP | 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PDIP32 |
| M37542F8FP | 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PDSO36 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| M37542M2-XXXFP | 制造商:RENESAS 制造商全稱(chēng):Renesas Technology Corp 功能描述:SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER |
| M37542M2-XXXGP | 制造商:RENESAS 制造商全稱(chēng):Renesas Technology Corp 功能描述:SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER |
| M37542M2-XXXHP | 制造商:RENESAS 制造商全稱(chēng):Renesas Technology Corp 功能描述:SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER |
| M37542M2-XXXSP | 制造商:RENESAS 制造商全稱(chēng):Renesas Technology Corp 功能描述:SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER |
| M37542M4-XXXFP | 制造商:RENESAS 制造商全稱(chēng):Renesas Technology Corp 功能描述:SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。