参数资料
型号: MC68HC05C5CP
厂商: MOTOROLA INC
元件分类: 微控制器/微处理器
英文描述: 8-BIT, MROM, 2.1 MHz, MICROCONTROLLER, PDIP40
封装: DIP-40
文件页数: 44/58页
文件大小: 166K
代理商: MC68HC05C5CP
Page 43
Section 8: Computer Operating Properly
MOTOROLA
MC68HC05C5 Specification Rev. 1.2
SECTION 8
COMPUTER OPERATING PROPERLY
8.1
INTRODUCTION
This device includes a "Watchdog" Computer Operating Properly (COP) feature as a
mask option. The COP is implemented with an 18-bit ripple counter. This provides a
timeout period of 64 milliseconds at a bus rate of 2 MHz. If the COP should timeout, a
system reset will occur and the device will be re-initialized in the same fashion as a POR
or external reset.
8.2
RESETTING THE COP
Preventing a COP reset is done by writing a "0" to the COPF bit. This action will reset the
counter and begin the timeout period again. The COPF bit is bit 0 of address $1FF0. A
read of address $1FF0 will result in the user defined ROM data at that location.
8.3
COP TEST FEATURES
For speeding up the COP test, a feature was added in the Self-Check mode to split the
18-bit counter into 6-bit and 12-bit counters clocked in parallel where the output of the 6-
bit counter drives the COP logic. Splitting the counter is accomplished by writing a "1" to
bit 7 of $1FF0. Writing a "0" to bit 7 of $1FF0 will reconnect the two halves of the COP
counter.
8.4
COP DURING WAIT MODE
The COP will continue to operate normally during WAIT mode. The software should pull
the device out of WAIT mode periodically and reset the COP by writing to the COPF bit to
prevent a COP reset.
8.5
COP DURING STOP MODE
STOP mode disables the oscillator circuit and thereby turns the clock off for the entire
device. The COP counter will be reset when STOP mode is entered. If a reset is used to
exit STOP mode, the COP counter will be reset after the 4064 cycles of delay after STOP
mode. If an IRQ is used to exit STOP mode, the COP counter will not be reset after the
4064-cycle delay and will have that many cycles already counted when control is returned
to the program.
相关PDF资料
PDF描述
MB89475PFV 8-BIT, 12.5 MHz, MICROCONTROLLER, PQFP48
MAH28151FXXXX 1 CHANNEL(S), 64K bps, SERIAL COMM CONTROLLER, CQFP68
MPC8245LZU300D 32-BIT, 300 MHz, RISC PROCESSOR, PBGA352
MPC8250AZUMHBB 32-BIT, 266 MHz, RISC PROCESSOR, PBGA480
MPC859DSLZP66 32-BIT, 66 MHz, RISC PROCESSOR, PBGA357
相关代理商/技术参数
参数描述
MC68HC05C8 制造商:MOTOROLA 制造商全称:Motorola, Inc 功能描述:PROGRAMMING REFRERENCE GUIDE
MC68HC05C8A 制造商:MOTOROLA 制造商全称:Motorola, Inc 功能描述:Microcontrollers
MC68HC05C8ACFN 制造商:Motorola Inc 功能描述:MicroController, 8-Bit, 44 Pin, Plastic, PLCC
MC68HC05C9 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:TECHNICAL DATA
MC68HC05C9A 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:Microcontrollers