- 您现在的位置：买卖IC网 > PDF目录80443 > MC68HC11D3CFN1 (ABILIS SYSTEMS) 8-BIT, MROM, 1 MHz, MICROCONTROLLER, PQCC44 PDF资料下载
参数资料
| 型号： | MC68HC11D3CFN1 |
| 厂商： | ABILIS SYSTEMS |
| 元件分类： | 微控制器/微处理器 |
| 英文描述： | 8-BIT, MROM, 1 MHz, MICROCONTROLLER, PQCC44 |
| 封装： | PLASTIC, LCC-44 |
| 文件页数： | 65/124页 |
| 文件大小： | 6875K |
| 代理商： | MC68HC11D3CFN1 |
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页当前第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页第83页第84页第85页第86页第87页第88页第89页第90页第91页第92页第93页第94页第95页第96页第97页第98页第99页第100页第101页第102页第103页第104页第105页第106页第107页第108页第109页第110页第111页第112页第113页第114页第115页第116页第117页第118页第119页第120页第121页第122页第123页第124页
RESETS AND INTERRUPTS
TECHNICAL DATA
5-1
SECTION 5
RESETS AND INTERRUPTS
Resets and interrupt operations load the program counter with a vector that points to
a new location from which instructions are to be fetched. A reset immediately stops
execution of the current instruction and forces the program counter to a known starting
address. Internal registers and control bits are initialized so the MCU can resume ex-
ecuting instructions. An interrupt temporarily suspends normal program execution
while an interrupt service routine is being executed. After an interrupt has been ser-
viced, the main program resumes as if there had been no interruption.
5.1 Resets
There are four possible sources of reset. Power-on reset (POR) and external reset
share the normal reset vector. The computer operating properly (COP) system and the
clock monitor each has its own vector.
5.1.1 Power-On Reset
A positive transition on VDD generates a power-on reset (POR), which is used only for
power-up conditions. POR cannot be used to detect drops in power supply voltages.
A 4064 tCYC (internal clock cycle) delay after the oscillator becomes active allows the
clock generator to stabilize. If RESET is at logical zero at the end of 4064 tCYC, the
CPU remains in the reset condition until goes to logical one.
It is important to protect the MCU during power transitions. Most M68HC11 systems
need an external circuit that holds the RESET pin low whenever VDD is below the min-
imum operating level. This external voltage level detector, or other external reset cir-
cuits, are the usual source of reset in a system. The POR circuit only initializes internal
circuitry during cold starts. Refer to Figure 2-3.
5.1.2 External Reset (RESET)
The CPU distinguishes between internal and external reset conditions by sensing
whether the reset pin rises to a logic one in less than two E-clock cycles after an inter-
nal device releases reset. When a reset condition is sensed, the RESET pin is driven
low by an internal device for four E-clock cycles, then released. Two E-clock cycles
later it is sampled. If the pin is still held low, the CPU assumes that an external reset
has occurred. If the pin is high, it indicates that the reset was initiated internally by ei-
ther the COP system or the clock monitor. It is not advisable to connect an external
resistor capacitor (RC) power-up delay circuit to the reset pin of M68HC11 devices be-
cause the circuit charge time constant can cause the device to misinterpret the type of
reset that occurred.
5.1.3 COP Reset
The MCU includes a COP system to help protect against software failures. When the
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
..
.
相关PDF资料 |
PDF描述 |
|---|---|
| M30260F3TGP-D3 | 16-BIT, FLASH, 20 MHz, MICROCONTROLLER, PQFP48 |
| M30263F6AFP-U9 | 16-BIT, FLASH, 20 MHz, MICROCONTROLLER, PDSO42 |
| M30263F6AFP | 16-BIT, FLASH, 20 MHz, MICROCONTROLLER, PDSO42 |
| M30302MCP-XXXFP | 16-BIT, MROM, 16 MHz, MICROCONTROLLER, PQFP100 |
| M30620FCMGP | 16-BIT, FLASH, 10 MHz, MICROCONTROLLER, PQFP100 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MC68HC11D3CFN2 | 制造商:MOTOROLA 制造商全称:Motorola, Inc 功能描述:Microcontrollers |
| MC68HC11D3CFN3 | 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:ROM-based high-performance microcontrollers |
| MC68HC11D3CFN4 | 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:ROM-based high-performance microcontrollers |
| MC68HC11D3CFU | 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:ROM-based high-performance microcontrollers |
| MC68HC11D3CFU1 | 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:ROM-based high-performance microcontrollers |
发布紧急采购，3分钟左右您将得到回复。