參數(shù)資料
型號(hào): SAH-C515A-4R
廠(chǎng)商: INFINEON TECHNOLOGIES AG
元件分類(lèi): 微控制器/微處理器
英文描述: 8-BIT, MROM, 24 MHz, MICROCONTROLLER, PQFP80
封裝: METRIC, PLASTIC, QFP-80
文件頁(yè)數(shù): 50/182頁(yè)
文件大?。?/td> 1917K
代理商: SAH-C515A-4R
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)當(dāng)前第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)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)第140頁(yè)第141頁(yè)第142頁(yè)第143頁(yè)第144頁(yè)第145頁(yè)第146頁(yè)第147頁(yè)第148頁(yè)第149頁(yè)第150頁(yè)第151頁(yè)第152頁(yè)第153頁(yè)第154頁(yè)第155頁(yè)第156頁(yè)第157頁(yè)第158頁(yè)第159頁(yè)第160頁(yè)第161頁(yè)第162頁(yè)第163頁(yè)第164頁(yè)第165頁(yè)第166頁(yè)第167頁(yè)第168頁(yè)第169頁(yè)第170頁(yè)第171頁(yè)第172頁(yè)第173頁(yè)第174頁(yè)第175頁(yè)第176頁(yè)第177頁(yè)第178頁(yè)第179頁(yè)第180頁(yè)第181頁(yè)第182頁(yè)
Semiconductor Group
8-5
1997-08-01
Fail Safe Mechanisms
C515A
8.1.4 Refreshing the Watchdog Timer
At the same time the watchdog timer is started, the 7-bit register WDTH is preset by the contents of
WDTREL.0 to WDTREL.6. Once started the watchdog cannot be stopped by software but can only
be refreshed to the reload value by first setting bit WDT (IEN0.6) and by the next instruction setting
SWDT (IEN1.6). Bit WDT will automatically be cleared during the second machine cycle after
having been set. For this reason, setting SWDT bit has to be a one cycle instruction (e.g. SETB
SWDT). This double-instruction refresh of the watchdog timer is implemented to minimize the
chance of an unintentional reset of the watchdog.
The reload register WDTREL can be written to at any time, as already mentioned. Therefore, a
periodical refresh of WDTREL can be added to the above mentioned starting procedure of the
watchdog timer. Thus a wrong reload value caused by a possible distortion during the write
operation to the WDTREL can be corrected by software.
8.1.5 Watchdog Reset and Watchdog Status Flag
lf the software fails to clear the watchdog in time, an internally generated watchdog reset is entered
at the counter state 7FFCH. The duration of the reset signal then depends on the prescaler
selection (either 8 cycles or 128 cycles). This internal reset differs from an external one only in so
far as the watchdog timer is not disabled and bit WDTS (watchdog timer status, bit 6 in SFR IP0) is
set. Figure 8-2 shows a block diagram of all reset requests in the C515A and the function of the
watchdog status flags. The WDTS flag is a flip-flop, which is set by a watchdog timer reset and
cleared by an external HW reset. Bit WDTS allows the software to examine from which source the
reset was activated. The watchdog timer status flag can also be cleared by software.
Figure 8-2
Watchdog Timer Status Flags and Reset Requests
MCS02756
WDT Reset Request
IP0 (A9H)
OWDS WDTS
OWD Reset Request
Set
Clear
External HW Reset Request
External HW-Power Down Request
Internal Bus
RESET
HWPD
Synchronization
Reset
Internal
< _ 1
相關(guān)PDF資料
PDF描述
SAH-C515C-LM 8-BIT, 10 MHz, MICROCONTROLLER, PQFP80
SAH-XC2210U-8F66R 32-BIT, FLASH, 66 MHz, RISC MICROCONTROLLER, PDSO38
SAH-XC2387A-104F80L 16-BIT, FLASH, 80 MHz, RISC MICROCONTROLLER, PQFP144
SAH-XC2387C-200F100L 32-BIT, FLASH, 100 MHz, RISC MICROCONTROLLER, PQFP144
SAH-XC2387C-136F100L 32-BIT, FLASH, 100 MHz, RISC MICROCONTROLLER, PQFP144
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SAH-C517A 制造商:INFINEON 制造商全稱(chēng):Infineon Technologies AG 功能描述:8-bit CMOS MICROCONTROLLER
SAHC684M50R501 制造商:SHARMA 制造商全稱(chēng):Sharma Electro Components,Inc 功能描述:Tantalum Capacitors
SAHC685M20R501 制造商:SHARMA 制造商全稱(chēng):Sharma Electro Components,Inc 功能描述:Tantalum Capacitors
SAHD106M25R501 制造商:SHARMA 制造商全稱(chēng):Sharma Electro Components,Inc 功能描述:Tantalum Capacitors
SAHD155M50R501 制造商:SHARMA 制造商全稱(chēng):Sharma Electro Components,Inc 功能描述:Tantalum Capacitors