参数资料
型号: CP82C88Z
厂商: Intersil
文件页数: 3/11页
文件大小: 0K
描述: IC CMOS BUS CONTROLLER 20DIP
标准包装: 360
应用: CMOS 总线控制器
电源电压: 4.5 V ~ 5.5 V
电流 - 电源: 1mA
工作温度: 0°C ~ 70°C
安装类型: 通孔
封装/外壳: 20-DIP(0.300",7.62mm)
供应商设备封装: 20-PDIP
包装: 管件
82C88
Pin Description
PIN
(Continued)
SYMBOL
AMWC
NUMBER
8
TYPE
O
DESCRIPTION
ADVANCED MEMORY WRITE COMMAND: The AMWC issues a memory write command earlier in the machine
cycle to give memory devices an early indication of a write instruction. Its timing is the same as a read command
signal. AMWC is active LOW.
MWTC
9
O
MEMORY WRITE COMMAND: This command line instructs the memory to record the data present on the data
bus. This signal is active LOW.
MRDC
7
O
MEMORY READ COMMAND: This command line instructs the memory to drive its data onto the data bus. MRDC
is active LOW.
INTA
14
O
INTERRUPT ACKNOWLEDGE: This command line tells an interrupting device that its interrupt has been
acknowledged and that it should drive vectoring information onto the data bus. This signal is active LOW.
MCE/PDEN
17
O
This is a dual function pin. MCE (IOB IS TIED LOW) Master Cascade Enable occurs during an interrupt sequence
and serves to read a Cascade Address from a master 82C59A Priority Interrupt Controller onto the data bus. The
MCE signal is active HIGH. PDEN (IOB IS TIED HIGH): Peripheral Data Enable enables the data bus transceiver
for the I/O bus that DEN performs for the system bus. PDEN is active LOW.
Functional Description
The command logic decodes the three 80C86, 8086, 80C88,
8088, 80186, 80188 or 8089 status lines (S0, S1, S2) to
determine what command is to be issued (see Table 1).
TABLE 1. COMMAND DECODE DEFINITION
IOB mode if I/O or peripherals dedicated to one processor
exist in a multi-processor system.
System Bus Mode
The 82C88 is in the System Bus mode if the IOB pin is
S2
0
0
0
0
S1
0
0
1
1
S0
0
1
0
1
PROCESSOR STATE
Interrupt Acknowledge
Read I/O Port
Write I/O Port
Halt
82C88
COMMAND
INTA
IORC
IOWC, AIOWC
None
strapped LOW. In this mode, no command is issued until a
specified time period after the AEN line is activated (LOW).
This mode assumes bus arbitration logic will inform the bus
controller (on the AEN line) when the bus is free for use.
Both memory and I/O commands wait for bus arbitration.
This mode is used when only one bus exists. Here, both I/O
and memory are shared by more than one processor.
Command Outputs
1
1
1
1
0
0
1
1
0
1
0
1
Code Access
Read Memory
Write Memory
Passive
MRDC
MRDC
MWTC, AMWC
None
The advanced write commands are made available to initiate
write procedures early in the machine cycle. This signal can
be used to prevent the processor from entering an
unnecessary wait state.
INTA (Interrupt Acknowledge) acts as an I/O read during an
interrupt cycle. Its purpose is to inform an interrupting device
I/O Bus Mode
The 82C88 is in the I/O Bus mode if the IOB pin is strapped
HIGH. In the I/O Bus mode, all I/O command lines IORC,
IOWC, AIOWC, INTA) are always enabled (i.e., not
dependent on AEN). When an I/O command is initiated by
the processor, the 82C88 immediately activates the
command lines using PDEN and DT/R to control the I/O bus
transceiver. The I/O command lines should not be used to
control the system bus in this configuration because no
arbitration is present. This mode allows one 82C88 Bus
Controller to handle two external busses. No waiting is
involved when the CPU wants to gain access to the I/O bus.
Normal memory access requires a “Bus Ready” signal (AEN
LOW) before it will proceed. It is advantageous to use the
3
that its interrupt is being acknowledged and that it should
place vectoring information onto the data bus.
The command outputs are:
MRDC - Memory Read Command
MWTC - Memory Write Command
IORC - I/O Read Command
IOWC - I/O Write Command
AMWC - Advanced Memory Write Command
AIOWC - Advanced I/O Write Command
INTA - Interrupt Acknowledge
FN2979.2
August 25, 2005
相关PDF资料
PDF描述
H1CXS-1436M IDC CABLE - HKC14S/AE14M/X
M3AAA-1606R IDC CABLE - MSC16A/MC16M/MSC16A
V375C12E150BG CONVERTER MOD DC/DC 12V 150W
GMC17DRES CONN EDGECARD 34POS .100 EYELET
GSM11DRTS CONN EDGECARD 22POS DIP .156 SLD
相关代理商/技术参数
参数描述
CP82C89 功能描述:输入/输出控制器接口集成电路 PERIPH BUS ARBITER 5V 8MHZ 20PDIP COM RoHS:否 制造商:Silicon Labs 产品: 输入/输出端数量: 工作电源电压: 最大工作温度:+ 85 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:QFN-64 封装:Tray
CP82C89S2064 制造商:Rochester Electronics LLC 功能描述:- Bulk
CP82C89Z 功能描述:输入/输出控制器接口集成电路 W/ANNEAL PERIPH BUS ARBITER 5V 8MHZ RoHS:否 制造商:Silicon Labs 产品: 输入/输出端数量: 工作电源电压: 最大工作温度:+ 85 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:QFN-64 封装:Tray
CP8300BT 功能描述:IC MCU 制造商:cypress semiconductor corp 系列:* 零件状态:最後搶購 标准包装:1
CP8300BTT 功能描述:IC MCU 制造商:cypress semiconductor corp 系列:* 零件状态:最後搶購 标准包装:1