參數(shù)資料
型號: AP87C54
廠商: INTEL CORP
元件分類: 微控制器/微處理器
英文描述: CHMOS SINGLE-CHIP 8-BIT MICROCONTROLLER WITH 16 KBYTES USER PROGRAMMABLE EPROM
中文描述: 8-BIT, OTPROM, 12 MHz, MICROCONTROLLER, PDIP40
封裝: PLASTIC, DIP-40
文件頁數(shù): 7/20頁
文件大?。?/td> 290K
代理商: AP87C54
AUTOMOTIVE 87C54/87C54-20
ONCE MODE
The ONCE (‘‘On-Circuit Emulation’’) Mode facilitates
testing and debugging of systems using the 87C54
without the 87C54 having to be removed from the
circuit. The ONCE Mode is invoked by:
1) Pull ALE low while the device is in reset and
PSEN is high;
2) Hold ALE low as RST is deactivated.
While the device is in ONCE Mode, the Port 0 pins
float and the other port pins and ALE and PSEN are
weakly pulled high. The oscillator circuit remains ac-
tive. While the 87C54 is in this mode, an emulator or
test CPU can be used to drive the circuit. Normal
operation is restored when a normal reset is applied.
RFI REDUCTION MODE
The RFI reduction feature can be used only if exter-
nal program memory is not required since this mode
disables the ALE pin during instruction code fetches.
By writing a logical one to the LSB of the Auxiliary
Register (address 08EH), the ALE is disabled for in-
struction code fetches and the output is weakly held
high. When a logical zero is written, the ALE pin is
enabled allowing it to generate the Address Latch
Enable signal. This bit is cleared by reset. Once dis-
abled, ALE remains disabled until it is reset by soft-
ware or until a hardware reset occurs.
Table 2. Status of the External Pins during Idle and Power Down
Mode
Program
Memory
ALE
PSEN
PORT0
PORT1
PORT2
PORT3
Idle
Internal
1
1
Data
Data
Data
Data
Idle
External
1
1
Float
Data
Address
Data
Power Down
Internal
0
0
Data
Data
Data
Data
Power Down
External
0
0
Float
Data
Data
Data
NOTE:
For more detailed information on the reduced power modes refer to current Embedded Applications Handbook, and Applica-
tion Note AP-252, ‘‘Designing with the 80C51BH.’’
7
相關(guān)PDF資料
PDF描述
AP87C54-20 CHMOS SINGLE-CHIP 8-BIT MICROCONTROLLER WITH 16 KBYTES USER PROGRAMMABLE EPROM
Applications2SK3132 Silicon N Channel MOS Type Chopper Regulator DC−DC Converter and Motor Drive Applications
APTM50DUM38TG Dual common source MOSFET Power Module
APTM50H10FT3G Full - Bridge MOSFET Power Module
APTM50H14FT3G Full - Bridge MOSFET Power Module
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AP87C54-20 制造商:INTEL 制造商全稱:Intel Corporation 功能描述:CHMOS SINGLE-CHIP 8-BIT MICROCONTROLLER WITH 16 KBYTES USER PROGRAMMABLE EPROM
AP8800 制造商:DIODES 制造商全稱:Diodes Incorporated 功能描述:350mA LED Step-Down Converter
AP-8800 制造商:GC Electronics 功能描述: 制造商:Winegard 功能描述:
AP8800_0912 制造商:DIODES 制造商全稱:Diodes Incorporated 功能描述:350mA LED Step-down Converter
AP8800A 制造商:DIODES 制造商全稱:Diodes Incorporated 功能描述:COST EFFECTIVE 28V BUCK 1-W LED DRIVER