參數(shù)資料
型號: ST6246BB6/XXX
廠商: STMICROELECTRONICS
元件分類: 微控制器/微處理器
英文描述: 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PDIP56
封裝: 0.600 INCH, PLASTIC, SDIP-56
文件頁數(shù): 13/73頁
文件大?。?/td> 1806K
代理商: ST6246BB6/XXX
Obsolete
Product(s)
- Obsolete
Product(s)
Obsolete
Product(s)
- Obsolete
Product(s)
20/73
ST62T46B/E46B
RESETS (Cont’d)
3.2.3 Watchdog Reset
The MCU provides a Watchdog timer function in
order to ensure graceful recovery from software
upsets. If the Watchdog register is not refreshed
before an end-of-count condition is reached, the
internal reset will be activated. This, amongst oth-
er things, resets the watchdog counter.
The MCU restarts just as though the Reset had
been generated by the RESET pin, including the
built-in stabilisation delay period.
3.2.4 Application Notes
No external resistor is required between VDD and
the Reset pin, thanks to the built-in pull-up device.
The POR circuit operates dynamically, in that it
triggers MCU initialization on detecting the rising
edge of VDD. The typical threshold is in the region
of 2 volts, but the actual value of the detected
threshold depends on the way in which VDD rises.
The POR circuit is NOT designed to supervise
static, or slowly rising or falling VDD.
3.2.5 MCU Initialization Sequence
When a reset occurs the stack is reset, the PC is
loaded with the address of the Reset Vector (locat-
ed in program ROM starting at address 0FFEh). A
jump to the beginning of the user program must be
coded at this address. Following a Reset, the In-
terrupt flag is automatically set, so that the CPU is
in Non Maskable Interrupt mode; this prevents the
initialisation routine from being interrupted. The in-
itialisation routine should therefore be terminated
by a RETI instruction, in order to revert to normal
mode and enable interrupts. If no pending interrupt
is present at the end of the initialisation routine, the
MCU will continue by processing the instruction
immediately following the RETI instruction. If, how-
ever, a pending interrupt is present, it will be serv-
iced.
Figure 12. Reset and Interrupt Processing
Figure 13. Reset Block Diagram
RESET
VECTOR
JP
JP:2 BYTES/4 CYCLES
RETI
RETI: 1 BYTE/2 CYCLES
INITIALIZATION
ROUTINE
VA00181
VDD
RESET
300k
2.8k
POWER
WATCHDOG RESET
CK
COUNTER
RESET
ST6
INTERNAL
RESET
fOSC
RESET
ON RESET
VA0200B
相關(guān)PDF資料
PDF描述
ST6260BB6 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PDIP20
ST6294B8/XXX 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PDIP28
ST62T94B8 8-BIT, OTPROM, 8 MHz, MICROCONTROLLER, PDIP28
ST62E85BG1 8-BIT, UVPROM, 8 MHz, MICROCONTROLLER, CQFP80
ST62P35BQ3/XXX 8-BIT, MROM, 4 MHz, MICROCONTROLLER, PQFP52
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ST6246B-EMU2 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:REAL TIME EMULATION DEVELOPMENT TOOLS FOR ST6 MCU FAMILY
ST6246-P/QFP 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:REAL TIME EMULATION DEVELOPMENT TOOLS FOR ST6 MCU FAMILY
ST6-24B20 功能描述:電源變壓器 SPLIT BOBBIN HORZ MOUNT XFMR RoHS:否 制造商:Triad Magnetics 功率額定值:12 VA 初級電壓額定值:115 V / 230 V 次級電壓額定值:12 V / 24 V 安裝風(fēng)格:SMD/SMT 一次繞組:Dual Primary Winding 二次繞組:Dual Secondary Winding 長度:2.5 in 寬度:2 in 高度:1.062 in
ST624OB-EMU2 制造商:STMicroelectronics 功能描述:ST62 EMULATOR
ST624X 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:8/16-Bit Micros