欧美成人免费电影,国产欧美一区二区三区精品酒店,精品国产a毛片,色网在线免费观看

參數資料
型號: MC68HC11A1VFU2
廠商: MOTOROLA INC
元件分類: 微控制器/微處理器
英文描述: HCMOS Single-Chip Microcontroller
中文描述: 8-BIT, 2 MHz, MICROCONTROLLER, PQFP64
封裝: QFP-64
文件頁數: 81/158頁
文件大小: 503K
代理商: MC68HC11A1VFU2
MC68HC11A8
TECHNICAL DATA
RESETS, INTERRUPTS, AND LOW POWER MODES
MOTOROLA
9-1
9
9 RESETS, INTERRUPTS, AND LOW POWER MODES
This section provides a description of the resets, interrupts, and low power modes. The
computer operating properly (COP) watchdog system and clock monitor are described
as part of the reset system. The interrupt description includes a flowchart to illustrate
how interrupts are executed.
9.1 Resets
The MCU has four possible types of reset: an active low external reset pin (RESET),
a power-on reset, a computer operating properly (COP) watchdog timer reset, and a
clock monitor reset.
9.1.1 External RESET Pin
The RESET pin is used to reset the MCU and allow an orderly software start-up pro-
cedure. When a reset condition is sensed, this pin is driven low by an internal device
for four E clock cycles, then released, and two E clock cycles later it is sampled. If the
pin is still low, it means that an external reset has occurred. If the pin is high, it implies
that the reset was initiated internally by either the watchdog timer (COP) or the clock
monitor (refer to
Figure 9-1
). This method of differentiation between internal and ex-
ternal reset conditions assumes that the reset pin will rise to a logic one in less than
two E clock cycles once it is released and that an externally generated reset should
stay active for at least eight E clock cycles.
Since there is EEPROM on chip, it is very important to control reset during power tran-
sitions. If the reset line is not held low while V
DD
is below its minimum operating level,
the EEPROM contents could be corrupted. Corruption occurs due to improper instruc-
tion execution when there is not sufficient voltage to execute instructions correctly.
Both EEPROM memories and the EEPROM based CONFIG register are subject to
this potential problem.
A low voltage inhibit (LVI) circuit which holds reset low whenever V
DD
is below its min-
imum operating level is required to protect against EEPROM corruption.
Figure 9-2
shows an example of reset circuits with LVI capabilities. The best circuit for a particular
application may be different from the suggested circuit.
9.1.2 Power-On Reset
The power-on reset occurs when a positive transition is detected on V
DD
. The power-
on reset is used strictly for power turn-on conditions and should not be used to detect
any drops in power
相關PDF資料
PDF描述
MC68HC11E0CB2 Microcontrollers
MC68S711E9CFN2 Microcontrollers
MC68HC711E20FS3 Microcontrollers
MC68L11E20FU2 Microcontrollers
MC68L11E0FU2 Microcontrollers
相關代理商/技術參數
參數描述
MC68HC11A1VP 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:8-Bit Microcontrollers
MC68HC11A1VP2 制造商:MOTOROLA 制造商全稱:Motorola, Inc 功能描述:HCMOS Single-Chip Microcontroller
MC68HC11A8 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:8-Bit Microcontrollers
MC68HC11A8BCFN2 制造商:MOTOROLA 制造商全稱:Motorola, Inc 功能描述:HCMOS Single-Chip Microcontroller
MC68HC11A8BCFU2 制造商:MOTOROLA 制造商全稱:Motorola, Inc 功能描述:HCMOS Single-Chip Microcontroller
主站蜘蛛池模板: 沙田区| 临高县| 海林市| 通江县| 来安县| 武隆县| 拜城县| 曲麻莱县| 五寨县| 定州市| 北宁市| 河曲县| 同仁县| 中山市| 定边县| 新化县| 即墨市| 永年县| 红安县| 温宿县| 阳曲县| 谷城县| 老河口市| 肃北| 鹤岗市| 平塘县| 合水县| 饶河县| 陵水| 方山县| 石家庄市| 温宿县| 鄄城县| 浦北县| 柘城县| 鄂伦春自治旗| 红原县| 潞城市| 雷山县| 石门县| 扎兰屯市|