82C88
March 1997
CMOS Bus Controller
Description
The Intersil 82C88 is a high performance CMOS Bus Con-
troller manufactured using a self-aligned silicon gate CMOS
process (Scaled SAJI IV). The 82C88 provides the control
and command timing signals for 80C86, 80C88, 8086, 8088,
8089, 80186, and 80188 based systems. The high output
drive capability of the 82C88 eliminates the need for addi-
tional bus drivers.
Static CMOS circuit design insures low operating power. The
Intersil advanced SAJI process results in performance equal
to or greater than existing equivalent products at a significant
power savings.
Features
• Compatible with Bipolar 8288
• Performance Compatible with:
- 80C86/80C88 . . . . . . . . . . . . . . . . . . . . . . . . . .(5/8MHz)
- 80186/80188 . . . . . . . . . . . . . . . . . . . . . . . . . .(6/8MHz)
- 8086/8088 . . . . . . . . . . . . . . . . . . . . . . . . . . . .(5/8MHz)
- 8089
• Provides Advanced Commands for Multi-Master
Busses
• Three-State Command Outputs
• Bipolar Drive Capability
• Scaled SAJI IV CMOS Process
• Single 5V Power Supply
• Low Power Operation
- ICCSB . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10µA (Max)
- ICCOP . . . . . . . . . . . . . . . . . . . . . . . . .1mA/MHz (Max)
• Operating Temperature Ranges
- C82C88 . . . . . . . . . . . . . . . . . . . . . . . . . .0
o
C to +70
o
C
- I82C88 . . . . . . . . . . . . . . . . . . . . . . . . . -40
o
C to +85
o
C
- M82C88 . . . . . . . . . . . . . . . . . . . . . . . -55
o
C to +125
o
C
Ordering Information
PART NUMBER
CP82C88
CP82C88-10
IP82C88
CS82C88
IS82C88
CD82C88
ID82C88
MD82C88/B
8406901RA
MR82C88/B
84069012A
SMD#
20 Pad
CLCC
SMD#
-55
o
C to +125
o
C
20 Ld
PLCC
20 Ld
CERDIP
PACKAGE
20 Ld PDIP
TEMPERATURE
RANGE
0
o
C to +70
o
C
0
o
C to +70
o
C
-40
o
C to +85
o
C
0
o
C to +70
o
C
-40
o
C to +85
o
C
0
o
C to +70
o
C
-40
o
C to +85
o
C
-55
o
C to +125
o
C
PKG.
NO.
E20.3
E20.3
E20.3
N20.35
N20.35
F20.3
F20.3
F20.3
F20.3
J20.A
J20.A
Pinouts
20 LEAD PDIP, CERDIP
TOP VIEW
IOB
CLK
S1
DT/ R
ALE
AEN
MRDC
AMWC
MWTC
1
2
3
4
5
6
7
8
9
20 V
CC
19 S0
18 S2
17 MCE/PDEN
16 DEN
15 CEN
14 INTA
13 IORC
12 AIOWC
11 IOWC
DT/ R
ALE
AEN
MRDC
AMWC
4
5
6
7
8
9
MWTC
10
GND
11
IOWC
12
AIOWC
13
IORC
20 LEAD PLCC, CLCC
TOP VIEW
CLK
V
CC
20
IOB
S1
S0
19
18 S2
17 MCE/PDEN
16 DEN
15 CEN
14 INTA
3
2
1
GND 10
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
http://www.intersil.com or 407-727-9207
|
Copyright
©
Intersil Corporation 1999
File Number
2979.1
4-333
82C88
Functional Diagram
S0
S1
S2
MRDC
MWTC
AMWC
IORC
IOWC
AIOWC
INTA
CLK
CONTROL
INPUT
AEN
CEN
IOB
CONTROL
LOGIC
CONTROL
SIGNAL
GENERATOR
DT/R
DEN
MCE/PDEN
ALE
ADDRESS LATCH,
DATA TRANSCEIVER,
AND INTERRUPT
CONTROL SIGNALS
STATUS
DECODER
COMMAND
SIGNAL
GENERATOR
MULTIBUS
TM
COMMAND
SIGNALS
V
CC
GND
Pin Description
PIN
SYMBOL
V
CC
GND
S0, S1, S2
NUMBER
20
10
19, 3, 18
I
TYPE
DESCRIPTION
V
CC
: The +5V power supply pin. A 0.1µF capacitor between pins 10 and 20 is recommended for decoupling.
GROUND.
STATUS INPUT PINS: These pins are the input pins from the 80C86, 80C88,8086/88, 8089 processors.
The 82C88 decodes these inputs to generate command and control signals at the appropriate time.
When Status pins are not in use (passive), command outputs are held HIGH (See Table1).
CLOCK: This is a CMOS compatible input which receives a clock signal from the 82C84A or 82C85 clock
generator and serves to establish when command/control signals are generated.
ADDRESS LATCH ENABLE: This signal serves to strobe an address into the address latches. This sig-
nal is active HIGH and latching occurs on the falling (HIGH to LOW) transition. ALE is intended for use
with transparent D type latches, such as the 82C82 and 82C83H.
DATA ENABLE: This signal serves to enable data transceivers onto either the local or system data bus.
This signal is active HIGH.
DATA TRANSMIT/RECEIVE: This signal establishes the direction of data flow through the transceivers.
A HIGH on this line indicates Transmit (write to I/O or memory) and a LOW indicates Receive (read from
I/O or memory).
ADDRESS ENABLE: AEN enables command outputs of the 82C88 Bus Controller a minimum of 110ns
(250ns maximum) after it becomes active (LOW). AEN going inactive immediately three-states the com-
mand output drivers. AEN does not affect the I/O command lines if the 82C88 is in the I/O Bus mode
(IOB tied HIGH).
COMMAND ENABLE: When this signal is LOW all 82C88 command outputs and the DEN and PDEN con-
trol outputs are forced to their Inactive state. When this signal is HIGH, these same outputs are enabled.
INPUT/OUTPUT BUS MODE: When the IOB pin is strapped HIGH, the 82C88 functions in the I/O Bus
mode. When it is strapped LOW, the 82C88 functions in the System Bus mode (See I/O Bus and System
Bus sections).
CLK
2
I
ALE
5
O
DEN
16
O
DT/R
4
O
AEN
6
I
CEN
15
I
IOB
1
I
Intel™ is a Registered Trademark of Intel Corporation
4-334
82C88
Pin Description
PIN
SYMBOL
AIOWC
NUMBER
12
(Continued)
TYPE
O
DESCRIPTION
ADVANCED I/O WRITE COMMAND: The AIOWC issues an I/O Write Command earlier in the machine
cycle to give I/O devices an early indication of a write instruction. Its timing is the same as a read com-
mand signal. AIOWC is active LOW.
I/O WRITE COMMAND: This command line instructs an I/O device to read the data on the data bus. The
signal is active LOW.
I/O READ COMMAND: This command line instructs an I/O device to drive its data onto the data bus. This
signal is active LOW.
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.
MEMORY WRITE COMMAND: This command line instructs the memory to record the data present on
the data bus. This signal is active LOW.
MEMORY READ COMMAND: This command line instructs the memory to drive its data onto the data
bus. MRDC is active LOW.
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.
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.
IOWC
11
O
IORC
13
O
AMWC
8
O
MWTC
9
O
MRDC
7
O
INTA
14
O
MCE/PDEN
17
O
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
82C88
COMMAND
INTA
IORC
IOWC, AIOWC
None
MRDC
MRDC
MWTC, AMWC
None
S2
0
0
0
0
1
1
1
1
S1
0
0
1
1
0
0
1
1
S0
0
1
0
1
0
1
0
1
PROCESSOR STATE
Interrupt Acknowledge
Read I/O Port
Write I/O Port
Halt
Code Access
Read Memory
Write Memory
Passive
cessor, 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 pro-
ceed. It is advantageous to use the IOB mode if I/O or
peripherals dedicated to one processor exist in a multi-pro-
cessor system.
System Bus Mode
The 82C88 is in the System Bus mode if the IOB pin is
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
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 unneces-
sary wait state.
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 depen-
dent on AEN). When an I/O command is initiated by the pro-
4-335
82C88
INTA (Interrupt Acknowledge) acts as an I/O read during an
interrupt cycle. Its purpose is to inform an interrupting device
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
Control Outputs
The control outputs of the 82C88 are Data Enable (DEN),
Data Transmit/Receive (DT/R) and Master Cascade Enable/
Peripheral Data Enable (MCE/PDEN). The DEN signal
determines when the external bus should be enabled onto
the local bus and the DT/R determines the direction of data
transfer. These two signals usually go to the chip select and
direction pins of a transceiver.
The MCE/PDEN pin changes function with the two modes of
the 82C88. When the 82C88 is in the IOB mode (IOB HIGH),
the PDEN signal serves as a dedicated data enable signal
for the I/O or Peripheral System bus.
Interrupt Acknowledge and MCE
The MCE signal is used during an interrupt acknowledge
cycle if the 82C88 is in the System Bus mode (IOB LOW).
During any interrupt sequence, there are two interrupt
acknowledge cycles that occur back to back. During the first
interrupt cycle no data or address transfers take place. Logic
should be provided to mask off MCE during this cycle. Just
before the second cycle begins the MCE signal gates a mas-
ter Priority Interrupt Controller’s (PIC) cascade address onto
the processor’s local bus where ALE (Address Latch Enable)
strobes it into the address latches. On the leading edge of
the second interrupt cycle, the addressed slave PIC gates an
interrupt vector onto the system data bus where it is read by
the processor.
If the system contains only one PIC, the MCE signal is not
used. In this case, the second Interrupt Acknowledge signal
gates the interrupt vector onto the processor bus.
Address Latch Enable and Halt
Address Latch Enable (ALE) occurs during each machine
cycle and serves to strobe the current address into the
82C82/82C83H address latches. ALE also serves to strobe
the status (S0, S1, S2) into a latch for halt state decoding.
Command Enable
The Command Enable (CEN) input acts as a command
qualifier for the 82C88. If the CEN pin is high, the 82C88
functions normally. If the CEN pin is pulled LOW, all com-
mand lines are held in their inactive state (not three-state).
This feature can be used to implement memory partitioning
and to eliminate address conflicts between system bus
devices and resident bus devices.
4-336
82C88
Absolute Maximum Ratings
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +8.0V
Input, Output or I/O Voltage . . . . . . . . . . . GND -0.5V to V
CC
+0.5V
ESD Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Class 1
Thermal Information
Thermal Resistance (Typical)
θ
JA
(
o
C/W)
θ
JC
(
o
C/W)
CERDIP Package . . . . . . . . . . . . . . . .
75
18
CLCC Package . . . . . . . . . . . . . . . . . .
85
22
PDIP Package . . . . . . . . . . . . . . . . . . .
75
N/A
PLCC Package . . . . . . . . . . . . . . . . . .
75
N/A
Storage Temperature Range . . . . . . . . . . . . . . . . . .-65
o
C to +150
o
C
Maximum Junction Temperature
Ceramic Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +175
o
C
Plastic Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +150
o
C
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . +300
o
C
(PLCC - Lead Tips Only)
Operating Conditions
Operating Voltage Range . . . . . . . . . . . . . . . . . . . . . +4.5V to +5.5V
Operating Temperature Range
C82C88. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0
o
C to +70
o
C
I82C88 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40
o
C to +85
o
C
M82C88 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55
o
C to +125
o
C
Die Characteristics
Gate Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Gates
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation
of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
DC Electrical Specifications
V
CC
= 5.0V
±
10%;
T
A
= 0
o
C to +70
o
C (C82C88);
T
A
= -40
o
C to +85
o
C (I82C88);
T
A
= -55
o
C to +125
o
C (M82C88)
MIN
2.0
2.2
-
V
CC
-0.8
-
3.0
V
CC
-0.4
3.0
V
CC
-0.4
-
-
-1.0
-50
-10.0
-
-
MAX
-
-
0.8
-
0.8
-
-
0.5
0.4
1.0
-300
10.0
10
1
UNITS
V
V
V
V
V
V
V
V
V
V
V
µA
µA
µA
µA
mA/MHz
I
OH
= -8.0mA
I
OH
= -2.5mA
I
OH
= -4.0mA
I
OH
= -2.5mA
I
OL
= +12.0mA
I
OL
= +8.0mA
V
IN
= GND or V
CC
, except S0, S1, S2,
DIP Pins 1-2, 6, 15
V
IN
= 2.0V, S0, S1, S2 (See Note 1)
V
O
= GND or V
CC
, IOB = GND, AEN = V
CC
,
DIP Pins 7-9, 11-14
V
CC
= 5.5V, V
IN
= V
CC
or GND, Outputs Open
V
CC
= 5.5V, Outputs Open (See Note 2)
TEST CONDITIONS
C82C88, I82C88
M82C88
SYMBOL
V
IH
V
IL
VIHC
VILC
V
OH
PARAMETER
Logical One Input Voltage
Logical Zero Input Voltage
CLK Logical One Input Voltage
CLK Logical Zero Input Voltage
Output High Voltage
Command Outputs
Output High Voltage
Control Outputs
V
OL
Output Low Voltage
Command Outputs
Output Low Voltage
Control Outputs
I
I
IBHH
IO
ICCSB
ICCOP
NOTES:
Input Leakage Current
Input Leakage Current-Status Bus
Output Leakage Current
Standby Power Supply
Operating Power Supply Current
1. IBHH should be measured after raising the V
IN
on S0, S1, S2 to V
CC
and then lowering to valid input high level of 2.0V.
2. ICCOP = 1mA/MHz of CLK cycle time (TCLCL)
Capacitance
SYMBOL
CIN
COUT
T
A
= +25
o
C
PARAMETER
Input Capacitance
Output Capacitance
TYPICAL
10
17
UNITS
pF
pF
TEST CONDITIONS
FREQ = 1MHz, all measurements are
referenced to device GND
4-337
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