INTEL INTEL386

Intel386™ EX Embedded
Microprocessor
Datasheet
Product Features
■
■
■
■
■
■
Static Intel386™ CPU Core
— Low Power Consumption
— Operating Power Supply
EXTB: 2.7 V to 3.6 V
EXTC: 4.5 V to 5.5 V
— Operating Frequency
20 MHz EXTB at 2.7 V to 3.6 V
25 MHz EXTB at 3.0 V to 3.6 V;
25/33 MHz EXTC at 4.5 V to 5.5 V
Transparent Power-management System
Architecture
— Intel System Management Mode
Architecture Extension for Truly
Compatible Systems
— Power Management Transparent to
Operating Systems and Application
Programs
— Programmable Power-management
Modes
Powerdown Mode
— Clock Stopping at Any Time
— Only 10–20 µA Typical CPU Sink
Current
Full 32-bit Internal Architecture
— 8-, 16-, 32-bit Data Types
— 8 General Purpose 32-bit Registers
Runs Intel386 Architecture Software in a
Cost-effective 16-bit Hardware
Environment
— Runs Same Applications and Operating
Systems as the Intel386 SX and Intel386
DX Processors
— Object Code Compatible with 8086,
80186, 80286, and Intel386 Processors
High-performance 16-bit Data Bus
— Two-clock Bus Cycles
— Address Pipelining Allows Use of
Slower, Inexpensive Memories
■
■
■
■
■
■
■
■
■
Extended Temperature Range
Integrated Memory Management Unit
— Virtual Memory Support
— Optional On-chip Paging
— 4 Levels of Hardware-enforced
Protection
— MMU Fully Compatible with MMUs of
the 80286 and Intel386 DX Processors
Virtual 8086 Mode Allows Execution of
8086 Software in a Protected and Paged
System
Large Uniform Address Space
— 64 Megabyte Physical
— 64 Terabyte Virtual
— 4 Gigabyte Maximum Segment Size
On-chip Debugging Support Including
Breakpoint Registers
Complete System Development Support
High Speed CHMOS Technology
Two Package Types
— 132-pin Plastic Quad Flatpack
— 144-pin Thin Quad Flatpack
Integrated Peripheral Functions
— Clock and Power Management Unit
— Chip-select Unit
— Interrupt Control Unit
— Timer/Counter Unit
— Watchdog Timer Unit
— Asynchronous Serial I/O Unit
— Synchronous Serial I/O Unit
— Parallel I/O Unit
— DMA and Bus Arbiter Unit
— Refresh Control Unit
— JTAG-compliant Test-logic Unit
This datasheet applies to devices marked EXTB and EXTC. If you require information about
devices marked EXSA or EXTA, refer to a previous revision of this datasheet, order number
272420-004.
Order Number: 272420-007
October 1998
Information in this document is provided in connection with Intel products. No license, express or implied, by estoppel or otherwise, to any intellectual
property rights is granted by this document. Except as provided in Intel’s Terms and Conditions of Sale for such products, Intel assumes no liability
whatsoever, and Intel disclaims any express or implied warranty, relating to sale and/or use of Intel products including liability or warranties relating to
fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. Intel products are not
intended for use in medical, life saving, or life sustaining applications.
Intel may make changes to specifications and product descriptions at any time, without notice.
Designers must not rely on the absence or characteristics of any features or instructions marked "reserved" or "undefined." Intel reserves these for
future definition and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to them.
The Intel386™ EX Microprocessor may contain design defects or errors known as errata which may cause the product to deviate from published
specifications. Current characterized errata are available on request.
Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing your product order.
Copies of documents which have an ordering number and are referenced in this document, or other Intel literature may be obtained by calling 1-800548-4725 or by visiting Intel's website at http://www.intel.com.
Copyright © Intel Corporation, 1998
*Third-party brands and names are the property of their respective owners.
Datasheet
Intel386™ EX Embedded Microprocessor
Contents
1.0
Introduction .................................................................................................................. 7
2.0
Pin Assignment ........................................................................................................... 8
3.0
Pin Description .......................................................................................................... 12
4.0
Functional Description........................................................................................... 19
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
5.0
Design Considerations ..........................................................................................23
5.1
5.2
5.3
6.0
Instruction Set ..................................................................................................... 23
Component and Revision Identifiers ................................................................... 24
Package Thermal Specifications .........................................................................24
Electrical Specifications ........................................................................................ 27
6.1
6.2
6.3
7.0
Clock Generation and Power Management Unit ................................................. 19
Chip-select Unit ................................................................................................... 19
Interrupt Control Unit ........................................................................................... 19
Timer/Counter Unit .............................................................................................. 20
Watchdog Timer Unit........................................................................................... 20
Asynchronous Serial I/O Unit ..............................................................................20
Synchronous Serial I/O Unit ................................................................................ 21
Parallel I/O Unit ................................................................................................... 21
DMA and Bus Arbiter Unit ................................................................................... 21
Refresh Control Unit............................................................................................22
JTAG Test-logic Unit ........................................................................................... 22
Maximum Ratings................................................................................................ 27
DC Specifications ................................................................................................ 28
AC Specifications ................................................................................................ 30
Bus Cycle Waveforms ............................................................................................47
Figures
1
2
3
4
5
6
7
8
9
10
Datasheet
Intel386™ EX Embedded Processor Block Diagram ............................................ 7
Intel386™ EX Embedded Processor 132-Pin PQFP Pin Assignment .................. 8
Intel386™ EX Embedded Processor 144-Pin TQFP Pin Assignment................. 10
Maximum Case Temperature vs. Frequency for Typical Power Values
(132-lead PQFP, Vcc = 5.5 V) ............................................................................. 25
Maximum Case Temperature vs. Frequency for Typical Power Values
(144-lead TQFP, Vcc = 5.5 V nominal) ................................................................ 25
Maximum Case Temperature vs. Frequency for Typical Power Values
(132-lead PQFP, Vcc = 3.6 V) ............................................................................. 26
Maximum Case Temperature vs. Frequency for Typical Power Values
(144-lead TQFP, Vcc = 3.6 V)..............................................................................26
Drive Levels and Measurement Points for AC Specifications (EXTC) ................ 30
Drive Levels and Measurement Points for AC Specifications (EXTB) ................ 31
AC Test Loads..................................................................................................... 42
3
Intel386™ EX Embedded Microprocessor
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
CLK2 Waveform .................................................................................................. 42
AC Timing Waveforms — Input Setup and Hold Timing ..................................... 43
AC Timing Waveforms — Output Valid Delay Timing ......................................... 44
AC Timing Waveforms — Output Valid Delay Timing for
External Late READY#........................................................................................ 44
AC Timing Waveforms — Output Float Delay and HLDA Valid Delay Timing .... 45
AC Timing Waveforms — RESET Setup and Hold Timing and Internal Phase .. 45
AC Timing Waveforms — Relative Signal Timing ............................................... 46
AC Timing Waveforms — SSIO Timing .............................................................. 46
AC Timing Waveforms — Timer/Counter Timing ................................................ 46
Basic Internal and External Bus Cycles .............................................................. 47
Nonpipelined Address Read Cycles.................................................................... 48
Pipelined Address Cycle ..................................................................................... 49
16-bit Cycles to 8-bit Devices (using BS8#) ........................................................ 50
Basic External Bus Cycles .................................................................................. 51
Nonpipelined Address Write Cycles .................................................................... 52
Halt Cycle ............................................................................................................ 53
Basic Refresh Cycle ............................................................................................ 54
Refresh Cycle During HOLD/HLDA .................................................................... 55
LOCK# Signal During Address Pipelining ........................................................... 56
Interrupt Acknowledge Cycles............................................................................. 56
1
2
3
4
5
6
7
8
9
10
11
12
132-Pin PQFP Pin Assignment ............................................................................. 9
144-Pin TQFP Pin Assignment ........................................................................... 11
Pin Type and Output State Nomenclature .......................................................... 12
Intel386™ EX Microprocessor Pin Descriptions ................................................. 13
Microprocessor Clocks Per Instruction................................................................ 23
Thermal Resistances (0°C/W) θJA, θJC ................................................................ 24
5 V Intel386 EXTC Processor Maximum Ratings ............................................... 27
3 V Intel386 EXTB Processor Maximum Ratings................................................ 27
5-Volt DC Characteristics .................................................................................... 28
3-Volt DC Characteristics .................................................................................... 29
5-Volt AC Characteristics .................................................................................... 32
3-Volt AC Characteristics .................................................................................... 37
Tables
4
Datasheet
Intel386™ EX Embedded Microprocessor
Revision History
This datasheet applies to devices marked EXTB and EXTC. If you require information about
devices marked EXSA or EXTA, refer to a previous revision of this datasheet, order number
272420-004.
Datasheet
Revision
Date
Description
007
10/98
The document was updated to the larger page size. All known device errata for
the datasheet have been incorporated into this new revision.
006
5/96
Corrections added.
005
12/95
This datasheet applied to the new EXTB and EXTC devices.
004
9/94
This datasheet applied to devices marked EXSA or EXTA.
5
Intel386™ EX Embedded Microprocessor
1.0
Introduction
The Intel386™ EXTB embedded processor operates at 20 or 25 MHz at 3 Volts nominal. The
Intel386 EXTC embedded processor operates at 25 or 33 MHz at 5 Volts. In this datasheet,
“Intel386 EX processor” refers to both the Intel386 EXTB and EXTC processors.
The Intel386 EX embedded processor is a highly integrated, 32-bit, fully static processor optimized
for embedded control applications. With a 16-bit external data bus, a 26-bit external address bus,
and Intel’s System Management Mode (SMM), the Intel386 EX microprocessor brings the vast
software library of Intel386 architecture to embedded systems. It provides the performance benefits
of 32-bit programming with the cost savings associated with 16-bit hardware systems.
Address
Data
Figure 1. Intel386™ EX Embedded Processor Block Diagram
Bus Interface
Unit
Chip-select
Unit
JTAG Unit
Address
Intel386™ CX Core
Core Enhancements
Processor
- A20 Gate Core
- CPU Reset
- SMM
Data
Clock and Power
Management Unit
DRAM Refresh
Control Unit
Watchdog Timer Unit
Bus Monitor
Asynchronous Serial I/O
2 channels
(16450 compatible)
Synchronous Serial I/O
1 channel, full duplex
Timer/counter Unit
3 channels
(82C54 compatible)
I/O Ports
INTR
Interrupt Control Unit
DMA Controller
2 channels
(8237A compatible)
and Bus Arbiter Unit
A2849-02
Datasheet
7
Intel386™ EX Embedded Microprocessor
2.0
Pin Assignment
132
131
130
129
128
127
126
125
124
123
122
121
120
119
118
117
116
115
114
113
112
111
110
109
108
107
106
105
104
103
102
101
100
P2.7/CTS0#
P2.6/TXD0
VSS
P2.5/RXD0
DACK0#/CS5#
VCC
P2.4/CS4#
P2.3/CS3#
P2.2/CS2#
P2.1/CS1#
P2.0/CS0#
VCC
SMIACT#
TRST#
DRQ1/RXD1
DRQ0/DCD1#
VSS
CLK2
WDTOUT
EOP#/CTS1#
DACK1#/TXD1
P1.7/HLDA
RESET
VCC
P1.6/HOLD
P1.5/LOCK#
P1.4/RI0#
P1.3/DSR0#
P1.2/DTR0#
CLKOUT
P1.1/RTS0#
P1.0/DCD0#
VSS
Figure 2. Intel386™ EX Embedded Processor 132-Pin PQFP Pin Assignment
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
TOP VIEW
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
67
FLT#
DSR1#/STXCLK
VSS
INT7/TMRGATE1
INT6/TMRCLK1
INT5/TMRGATE0
INT4/TMRCLK0
BUSY#/TMRGATE2
ERROR#/TMROUT2
NMI
PEREQ/TMRCLK2
VCC
P3.7/COMCLK
P3.6/PWRDOWN
P3.5/INT3
P3.4/INT2
VSS
P3.3/INT1
VCC
P3.2/INT0
RTS1#/SSIOTX
RI1#/SSIORX
DTR1#/SRXCLK
TCK
P3.1/TMROUT1/INT8
P3.0/TMROUT0/INT9
SMI#
A25
VCC
A24
VSS
A23
A22
RD#
WR#
VSS
BLE#
VCC
BHE#
ADS#
NA#
A1
A2
A3
A4
VSS
VCC
A5
A6
A7
A8
A9
A10
A11
A12
A13
A14
A15
A16/CAS0
VCC
A17/CAS1
A18/CAS2
A19
VSS
A20
A21
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
UCS#
CS6#/REFRESH#
VSS
LBA#
D0
D1
D2
D3
VCC
D4
D5
D6
D7
D8
VCC
D9
VSS
D10
D11
D12
D13
D14
D15
TDO
TDI
TMS
M/IO#
VCC
D/C#
W/R#
VSS
READY#
BS8#
Note:
NC = No Connection
A2212-02
8
Datasheet
Intel386™ EX Embedded Microprocessor
Table 1.
132-Pin PQFP Pin Assignment
Pin
Datasheet
Symbol
Pin
Symbol
Pin
Symbol
Pin
Symbol
1
UCS#
34
RD#
67
A22
100
VSS
2
CS6#/REFRESH#
35
WR#
68
A23
101
P1.0/DCD0#
3
VSS
36
VSS
69
VSS
102
P1.1/RTS0#
4
LBA#
37
BLE#
70
A24
103
CLKOUT
5
D0
38
VCC
71
VCC
104
P1.2/DTR0#
6
D1
39
BHE#
72
A25
105
P1.3/DSR0#
7
D2
40
ADS#
73
SMI#
106
P1.4/RI0#
8
D3
41
NA#
74
P3.0/TMROUT0/INT9
107
P1.5/LOCK#
9
VCC
42
A1
75
P3.1/TMROUT1/INT8
108
P1.6/HOLD
10
D4
43
A2
76
TCK
109
VCC
11
D5
44
A3
77
DTR1#/SRXCLK
110
RESET
12
D6
45
A4
78
RI1#/SSIORX
111
P1.7/HLDA
13
D7
46
VSS
79
RTS1#/SSIOTX
112
DACK1#/TXD1
14
D8
47
VCC
80
P3.2/INT0
113
EOP#/CTS1#
15
Vcc
48
A5
81
VCC
114
WDTOUT
16
D9
49
A6
82
P3.3/INT1
115
CLK2
17
Vss
50
A7
83
VSS
116
VSS
18
D10
51
A8
84
P3.4/INT2
117
DRQ0/DCD1#
19
D11
52
A9
85
P3.5/INT3
118
DRQ1/RXD1
20
D12
53
A10
86
P3.6/PWRDOWN
119
TRST#
21
D13
54
A11
87
P3.7/COMCLK
120
SMIACT#
22
D14
55
A12
88
VCC
121
VCC
23
D15
56
A13
89
PEREQ/TMRCLK2
122
P2.0/CS0#
24
TDO
57
A14
90
NMI
123
P2.1/CS1#
25
TDI
58
A15
91
ERROR#/TMROUT2
124
P2.2/CS2#
26
TMS
59
A16/CAS0
92
BUSY#/TMRGATE2
125
P2.3/CS3#
27
M/IO#
60
VCC
93
INT4/TMRCLK0
126
P2.4/CS4#
28
VCC
61
A17/CAS1
94
INT5/TMRGATE0
127
VCC
29
D/C#
62
A18/CAS2
95
INT6/TMRCLK1
128
DACK0#/CS5#
30
W/R#
63
A19
96
INT7/TMRGATE1
129
P2.5/RXD0
31
VSS
64
VSS
97
VSS
130
VSS
32
READY#
65
A20
98
DSR1#/STXCLK
131
P2.6/TXD0
33
BS8#
66
A21
99
FLT#
132
P2.7/CTS0#
9
Intel386™ EX Embedded Microprocessor
144
143
142
141
140
139
138
137
136
135
134
133
132
131
130
129
128
127
126
125
124
123
122
121
120
119
118
117
116
115
114
113
112
111
110
109
VSS
P2.7/CTS0#
P2.6/TXD0
VSS
P2.5/RXD0
DACK0#/CS5#
VCC
P2.4/CS4#
P2.3/CS3#
P2.2/CS2#
P2.1/CS1#
P2.0/CS0#
VSS
VCC
SMIACT#
TRST#
DRQ1/RXD1
DRQ0/DCD1#
VSS
CLK2
WDTOUT
EOP#/CTS1#
DACK1#/TXD1
P1.7/HLDA
VSS
RESET
VCC
P1.6/HOLD
P1.5/LOCK#
P1.4/RI0#
P1.3/DSR0#
P1.2/DTR0#
CLKOUT
P1.1/RTS0#
P1.0/DCD0#
VSS
Figure 3. Intel386™ EX Embedded Processor 144-Pin TQFP Pin Assignment
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
TOP VIEW
108
107
106
105
104
103
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
VSS
FLT#
DSR1#/STXCLK
VSS
INT7/TMRGATE1
INT6/TMRCLK1
INT5/TMRGATE0
INT4/TMRCLK0
BUSY#/TMRGATE2
ERROR#/TMROUT2
NMI
VSS
PEREQ/TMRCLK2
VCC
P3.7/COMCLK
P3.6/PWRDOWN
P3.5/INT3
P3.4/INT2
VSS
P3.3/INT1
VCC
P3.2/INT0
RTS1#/SSIOTX
RI1#/SSIORX
DTR1#/SRXCLK
VSS
TCK
P3.1/TMROUT1/INT8
P3.0/TMROUT0/INT9
SMI#
A25
VCC
A24
VSS
A23
A22
RD#
WR#
VSS
BLE#
VCC
BHE#
ADS#
NA#
A1
A2
VSS
A3
A4
VSS
VCC
A5
A6
A7
A8
A9
A10
A11
A12
VSS
A13
A14
A15
A16/CAS0
VCC
A17/CAS1
A18/CAS2
A19
VSS
A20
A21
VSS
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
UCS#
CS6#/REFRESH#
VSS
LBA#
D0
D1
D2
D3
VCC
D4
VSS
D5
D6
D7
D8
VCC
D9
VSS
D10
D11
D12
D13
D14
VSS
D15
TDO
TDI
TMS
M/IO#
VCC
D/C#
W/R#
VSS
READY#
BS8#
VSS
A2213-03
10
Datasheet
Intel386™ EX Embedded Microprocessor
Table 2.
144-Pin TQFP Pin Assignment
Pin
Datasheet
Symbol
Pin
Symbol
Pin
Symbol
Pin
Symbol
1
UCS#
37
RD#
73
A22
109
VSS
2
CS6#/REFRESH#
38
WR#
74
A23
110
P1.0/DCD0#
3
VSS
39
VSS
75
VSS
111
P1.1/RTS0#
4
LBA#
40
BLE#
76
A24
112
CLKOUT
5
D0
41
VCC
77
VCC
113
P1.2/DTR0#
6
D1
42
BHE#
78
A25
114
P1.3/DSR0#
7
D2
43
ADS#
79
SMI#
115
P1.4/RI0#
8
D3
44
NA#
80
P3.0/TMROUT0/INT9
116
P1.5/LOCK#
9
VCC
45
A1
81
P3.1/TMROUT1/INT8
117
P1.6/HOLD
10
D4
46
A2
82
TCK
118
VCC
11
VSS
47
VSS
83
VSS
119
RESET
12
D5
48
A3
84
DTR1#/SRXCLK
120
VSS
13
D6
49
A4
85
RI1#/SSIORX
121
P1.7/HLDA
14
D7
50
VSS
86
RTS1#/SSIOTX
122
DACK1#/TXD1
15
D8
51
VCC
87
P3.2/INT0
123
EOP#/CTS1#
16
VCC
52
A5
88
VCC
124
WDTOUT
17
D9
53
A6
89
P3.3/INT1
125
CLK2
18
VSS
54
A7
90
VSS
126
VSS
19
D10
55
A8
91
P3.4/INT2
127
DRQ0/DCD1#
20
D11
56
A9
92
P3.5/INT3
128
DRQ1/RXD1
21
D12
57
A10
93
P3.6/PWRDOWN
129
TRST#
22
D13
58
A11
94
P3.7/COMCLK
130
SMIACT#
23
D14
59
A12
95
VCC
131
V CC
24
VSS
60
VSS
96
PEREQ/TMRCLK2
132
V SS
25
D15
61
A13
97
VSS
133
P2.0/CS0#
26
TDO
62
A14
98
NMI
134
P2.1/CS1#
27
TDI
63
A15
99
ERROR#/TMROUT2
135
P2.2/CS2#
28
TMS
64
A16/CAS0
100
BUSY#/TMRGATE2
136
P2.3/CS3#
29
M/IO#
65
VCC
101
INT4/TMRCLK0
137
P2.4/CS4#
30
VCC
66
A17/CAS1
102
INT5/TMRGATE0
138
V CC
31
D/C#
67
A18/CAS2
103
INT6/TMRCLK1
139
DACK0#/CS5#
32
W/R#
68
A19
104
INT7/TMRGATE1
140
P2.5/RXD0
33
VSS
69
VSS
105
VSS
141
VSS
34
READY#
70
A20
106
DSR1#/STXCLK
142
P2.6/TXD0
35
BS8#
71
A21
107
FLT#
143
P2.7/CTS0#
36
VSS
72
VSS
108
VSS
144
VSS
11
Intel386™ EX Embedded Microprocessor
3.0
Pin Description
Table 4 lists the Intel386 EX embedded processor pin descriptions. Table 3 defines the
abbreviations used in the Type and Output States columns of Table 4.
Table 3.
Pin Type and Output State Nomenclature
Symbol
Description
Pin Type
#
I
O
I/O
I/OD
ST
P
G
The named signal is active low.
Standard TTL input signal.
Standard CMOS output signal.
Input and output signal.
Input and open-drain output signal.
Schmitt-triggered input signal.
Power pin.
Ground pin.
H(1)
H(0)
H(Z)
H(Q)
H(X)
Output driven to VCC during Bus Hold
Output driven to VSS during Bus Hold
Output floats during Bus Hold
Output remains active during Bus Hold
Output retains current state during Bus Hold
Output State
R(WH)
R(WL)
R(1)
R(0)
R(Z)
R(Q)
R(X)
†
12
Output Weakly Held at VCC during Reset
Output Weakly Held at VSS during Reset
Output driven to VCC during Reset
Output driven to VSS during Reset
Output floats during Reset
Output remains active during Reset
Output retains current state during Reset
I(1)†
I(0)
I(Z)
I(Q)
I(X)
Output driven to VCC during Idle Mode
Output driven to VSS during Idle Mode
Output floats during Idle Mode
Output remains active during Idle Mode
Output retains current state during Idle Mode
P(1)
P(0)
P(Z)
P(Q)
P(X)
Output driven to VCC during Powerdown Mode
Output driven to VSS during Powerdown Mode
Output floats during Powerdown Mode
Output remains active during Powerdown Mode
Output retains current state during Powerdown Mode
The idle mode output states assume that no internal bus master (DMA or RCU) has control of the bus
during idle mode
Datasheet
Intel386™ EX Embedded Microprocessor
Table 4.
Intel386™ EX Microprocessor Pin Descriptions (Sheet 1 of 6)
Symbol
Type
Output States
Name and Function
A25:1
O
H(Z)
R(1)
I(1)
P(1)
Address Bus outputs physical memory or port I/O addresses.
These signals are valid when ADS# is active and remain valid
until the next T1, T2P, or Ti. During HOLD cycles they are driven
to a high-impedance state. A18:16 are multiplexed with CAS2:0.
ADS#
O
H(Z)
R(1)
I(1)
P(1)
Address Status indicates that the processor is driving a valid
bus-cycle definition and address (W/R#, D/C#, M/IO#, A25:1,
BHE#, BLE#) onto its pins.
BHE#
O
H(Z)
R(0)
I(X)
P(0)
Byte High Enable indicates that the processor is transferring a
high data byte.
BLE#
O
H(Z)
R(0)
I(X)
P(1)
Byte Low Enable indicates that the processor is transferring a
low data byte.
BS8#
I
Bus Size indicates that an 8-bit device is currently being
addressed.
BUSY#
I
Busy indicates that the math coprocessor is busy. If BUSY# is
sampled LOW at the falling edge of RESET, the processor
performs an internal self test. BUSY# is multiplexed with
TMRGATE2 and has a temporary weak pull-up resistor.
CAS2:0
O
CLK2
ST
CLKOUT
O
COMCLK
I
CS4:0#
O
H(1)
R(WH)
I(Q)
P(X)
Chip-selects are activated when the address of a memory or I/O
bus cycle is within the address region programmed by the user.
They are multiplexed as follows: CS6# with REFRESH#, CS5#
with DACK0#, and CS4:0# with P2.4:0.
CS6:5#
O
H(1)
R(1)
I(Q)
P(X)
Chip-selects are activated when the address of a memory or I/O
bus cycle is within the address region programmed by the user.
They are multiplexed as follows: CS6# with REFRESH#, CS5#
with DACK0#, and CS4:0# with P2.4:0.
CTS1:0#
I
H(Z)
R(1)
I(1)
P(1)
Cascade Address carries the slave address information from
the 8259A master interrupt module during interrupt acknowledge
bus cycles. CAS2:0 are multiplexed with A18:16.
Clock Input is connected to an external clock that provides the
fundamental timing for the device.
H(Q)
R(Q)
I(Q)
P(0)
CLKOUT is a PH1P clock output.
Serial Communications Baud Clock is an alternate clock
source for the asynchronous serial ports. COMCLK is
multiplexed with P3.7 and has a temporary weak pull-down
resistor.
Clear to Send SIO1 and SIO0 prevent the transmission of data
to the asynchronous serial port’s RXD1 and RXD0 pins,
respectively. CTS1# is multiplexed with EOP#, and CTS0# is
multiplexed with P2.7. CTS1# requires an external pull-up
resistor. Both have temporary weak pull-up resistors.
NOTES:
1. X if clock source is internal; Q if clock source is external
2. Q if JTAG unit is shifting out data, Z if it is not
Datasheet
13
Intel386™ EX Embedded Microprocessor
Table 4.
Intel386™ EX Microprocessor Pin Descriptions (Sheet 2 of 6)
Symbol
Type
Output States
Name and Function
D15:0
I/O
H(Z)
R(Z)
P(Z)
Data Bus inputs data during memory read, I/O read, and
interrupt acknowledge cycles and outputs data during memory
and I/O write cycles. During writes, this bus is driven during
phase 2 of T1 and remains active until phase 2 of the next T1,
T1P, or Ti. During reads, data is latched on the falling edge of
phase 2.
DACK1:0#
O
H(1)
R(1)
I(Q)
P(X)
DMA Acknowledge 1 and 0 signal to an external device that the
processor has acknowledged the corresponding DMA request
and is relinquishing the bus. DACK1# is multiplexed with TXD1,
and DACK0# is multiplexed with CS5#.
D/C#
O
H(Z)
R(1)
I(0)
P(0)
Data/Control indicates whether the current bus cycle is a data
cycle (memory or I/O read or write) or a control cycle (interrupt
acknowledge, halt, or code fetch).
DCD1:0
I
Data Carrier Detect SIO1 and SIO0 indicate that the modem or
data set has detected the corresponding asynchronous serial
channel’s data carrier. DCD1# is multiplexed with DRQ0, and
DCD0# is multiplexed with P1.0 and has a temporary weak pullup resistor.
DRQ1:0
I
DMA External Request 1 and 0 indicate that a peripheral
requires DMA service. DRQ1 is multiplexed with RXD1, and
DRQ0 is multiplexed with DCD1#.
DSR1:0#
I
Data Set Ready SIO1 and SIO0 indicate that the modem or data
set is ready to establish a communication link with the
corresponding asynchronous serial channel. DSR1# is
multiplexed with STXCLK and has a permanent weak pull-up
resistor, and DSR0# is multiplexed with P1.3 and has a
temporary weak pull-up resistor.
DTR1:0#
O
H(X)
R(WH)
I(X)
P(X)
Data Terminal Ready SIO1 and SIO0 indicate that the
corresponding asynchronous serial channel is ready to establish
a communication link with the modem or data set. DTR1# is
multiplexed with SRXCLK, and DTR0# is multiplexed with P1.2.
I/OD
H(Z)
R(WH)
I(Z)
P(Z)
End of Process indicates that the processor has reached
terminal count during a DMA transfer. An external device can
also pull this pin LOW. EOP# is multiplexed with CTS1#.
EOP#
ERROR#
Error indicates that the math coprocessor has an error condition.
ERROR# is multiplexed with TMROUT2 and has a temporary
weak pull-up resistor.
I
FLT#
I
HLDA
O
HOLD
I
Float forces all bidirectional and output signals except TDO to a
high-impedance state. It has a permanent weak pull-up resistor.
This pin should be tied to VCC through a 3 to 7 KOhm pull-up
resistor.
H(1)
R(WL)
I(Q)
P(X)
Bus Hold Acknowledge indicates that the processor has
surrendered control of its local bus to another bus master. HLDA
is multiplexed with P1.7.
Bus Hold Request allows another bus master to request control
of the local bus. HLDA active indicates that bus control has been
granted. HOLD is multiplexed with P1.6. It has a temporary weak
pull-down resistor.
NOTES:
1. X if clock source is internal; Q if clock source is external
2. Q if JTAG unit is shifting out data, Z if it is not
14
Datasheet
Intel386™ EX Embedded Microprocessor
Table 4.
Intel386™ EX Microprocessor Pin Descriptions (Sheet 3 of 6)
Symbol
Type
Output States
Name and Function
Interrupt Requests are maskable inputs that cause the CPU to
suspend execution of the current program and then execute an
interrupt acknowledge cycle. They are multiplexed as follows:
INT9 with TMROUT0 and P3.0, INT8 with TMROUT1 and P3.1,
INT7 with TMRGATE1, INT6 with TMRCLK1, INT5 with
TMRGATE0, INT4 with TMRCLK0, and INT3:0 with P3.5:2.
INT9, INT8, and INT3:0 have temporary weak pull-down
resistors.
INT9:0
I
LBA#
O
H(1)
R(1)
I(Q)
P(X)
Local Bus Access is asserted whenever the processor provides
the READY# signal to terminate a bus transaction. This occurs
when an internal peripheral address is accessed or when the
chip-select unit provides the READY# signal.
LOCK#
O
H(Z)
R(WH)
I(X)
P(X)
Bus Lock prevents other bus masters from gaining control of the
system bus.
H(Z)
R(0)
I(1)
P(1)
LOCK# is multiplexed with P1.5.
Memory/IO Indicates whether the current bus cycle is a memory
cycle or an I/O cycle. When M/IO# is HIGH, the bus cycle is a
memory cycle; when M/IO# is LOW, the bus cycle is an I/O cycle.
M/IO#
O
NA#
I
NMI
ST
Nonmaskable Interrupt Request is a non-maskable input that
causes the CPU to suspend execution of the current program
and execute an interrupt acknowledge cycle.
I
Processor Extension Request indicates that the math
coprocessor has data to transfer to the processor. PEREQ is
multiplexed with TMRCLK2 and has a temporary weak pull-down
resistor.
PEREQ
Next Address requests address pipelining.
P1.5:0
I/O
H(X)
R(WH)
I(X)
P(X)
Port 1, Pins 7:0 are multipurpose bidirectional port pins. They
are multiplexed as follows: P1.7 with HLDA, P1.6 with HOLD,
P1.5 with LOCK#, P1.4 with RI0#, P1.3 with DSR0#, P1.2 with
DTR0#, P1.1 with RTS0#, and P1.0 with DCD0#.
P1.7:6
I/O
H(X)
R(WL)
I(X)
P(X)
Port 1, Pins 7:0 are multipurpose bidirectional port pins. They
are multiplexed as follows: P1.7 with HLDA, P1.6 with HOLD,
P1.5 with LOCK#, P1.4 with RI0#, P1.3 with DSR0#, P1.2 with
DTR0#, P1.1 with RTS0#, and P1.0 with DCD0#.
P2.7,4:0
I/O
H(X)
R(WH)
I(X)
P(X)
Port 2, Pins 7:0 are multipurpose bidirectional port pins. They
are multiplexed as follows: P2.7 with CTS0#, P2.6 with TXD0,
P2.5 with RXD0, and P2.4:0 with CS4:0#.
P2.6:5
I/O
H(X)
R(WL)
I(X)
P(X)
Port 2, Pins 7:0 are multipurpose bidirectional port pins. They
are multiplexed as follows: P2.7 with CTS0#, P2.6 with TXD0,
P2.5 with RXD0, and P2.4:0 with CS4:0#.
P3.7:0
I/O
H(X)
R(WL)
I(X)
P(X)
Port 3, Pins 7:0 are multipurpose bidirectional port pins. They
are multiplexed as follows: P3.7 with COMCLK, P3.6 with
PWRDOWN, P3.5:2 with INT3:0, and P3.1:0 with TMROUT1:0
and INT8:9.
NOTES:
1. X if clock source is internal; Q if clock source is external
2. Q if JTAG unit is shifting out data, Z if it is not
Datasheet
15
Intel386™ EX Embedded Microprocessor
Table 4.
Intel386™ EX Microprocessor Pin Descriptions (Sheet 4 of 6)
Symbol
Type
Output States
Name and Function
PWRDOWN
O
H(Q)
R(WL)
I(X)
P(1)
Powerdown indicates that the processor is in powerdown mode.
PWRDOWN is multiplexed with P3.6.
RD#
O
H(1)
R(1)
I(1)
P(1)
Read Enable indicates that the current bus cycle is a read cycle.
READY#
I/O
H(Z)
R(Z)
I(Z)
P(Z)
Ready indicates that the current bus transaction has completed.
An external device or an internal signal can drive READY#.
Internally, the chip-select wait-state logic can generate the ready
signal and drive the READY# pin active.
RESET
ST
REFRESH#
O
RI1:0#
I
RTS1#
O
H(X)
R(WL)
I(X)
P(X)
Request-to-send SIO1 and SIO0 indicate that corresponding
asynchronous serial channel is ready to exchange data with the
modem or data set. RTS1# is multiplexed with SSIOTX, and
RTS0# is multiplexed with P1.1.
RTS0#
O
H(X)
R(WH)
I(X)
P(X)
Request-to-send SIO1 and SIO0 indicate that corresponding
asynchronous serial channel is ready to exchange data with the
modem or data set. RTS1# is multiplexed with SSIOTX, and
RTS0# is multiplexed with P1.1.
RXD1:0
SMI#
SMIACT#
Reset suspends any operation in progress and places the
processor into a known reset state.
H(1)
R(1)
I(Q)
P(X)
Ring Indicator SIO1 and SIO0 indicate that the modem or data
set has received a telephone ringing signal. RI1# is multiplexed
with SSIORX, and RI0# is multiplexed with P1.4 and has a
temporary weak pull-up resistor.
Receive Data SIO1 and SIO0 accept serial data from the
modem or data set to the corresponding asynchronous serial
channel. RXD1 is multiplexed with DRQ1, and RXD0 is
multiplexed with P2.5 and has a temporary weak pull-down
resistor.
I
System Management Interrupt invokes System Management
Mode (SMM). SMI# is the highest priority external interrupt. It is
latched on its falling edge and forces the CPU into SMM upon
completion of the current instruction. SMI# is recognized on an
instruction boundary and at each iteration for repeat string
instructions. SMI# cannot interrupt LOCKed bus cycles or a
currently executing SMM. When the processor receives a
second SMI# while in SMM, it latches the second SMI# on the
SMI# falling edge. However, the processor must exit SMM by
executing a resume instruction (RSM) before it can service the
second SMI#. SMI# has a permanent weak pull-up resistor.
ST
O
Refresh indicates that the current bus cycle is a refresh cycle.
REFRESH# is multiplexed with CS6#.
H(1)
R(1)
I(X)
P(X)
System Management Interrupt Active indicates that the
processor is operating in System Management Mode (SMM). It
is asserted when the processor initiates an SMM sequence and
remains asserted (LOW) until the processor executes the
resume instruction (RSM).
NOTES:
1. X if clock source is internal; Q if clock source is external
2. Q if JTAG unit is shifting out data, Z if it is not
16
Datasheet
Intel386™ EX Embedded Microprocessor
Table 4.
Intel386™ EX Microprocessor Pin Descriptions (Sheet 5 of 6)
Symbol
Type
Output States
SRXCLK
I/O
H(Q)
R(WH)
I(Q)
P(X)/P(Q)Note 1
SSIORX
I
Name and Function
SSIO Receive Clock synchronizes data being accepted by the
synchronous serial port. SRXCLK is multiplexed with DTR1#.
SSIO Receive Serial Data accepts serial data (most-significant
bit first) being sent to the synchronous serial port. SSIORX is
multiplexed with RI1#.
SSIOTX
O
H(Q)
R(WL)
I(Q)
P(X)/P(Q)Note 1
STXCLK
I/O
H(Q)
R(WH)
I(Q)
P(X)/P(Q)Note 1
SSIO Transmit Serial Data sends serial data (most-significant
bit first) from the synchronous serial port. SSIOTX is multiplexed
with RTS1#.
Intel does not specify a data hold time for SSIOTX. Slower
external devices may require additional hardware to properly
interface the SSIO unit.
SSIO Transmit Clock synchronizes data being sent by the
synchronous serial port. STXCLK is multiplexed with DSR1.
TCK
I
TAP (Test Access Port) Controller Clock provides the clock
input for the JTAG logic. It has a permanent weak pull-up
resistor.
TDI
I
TAP (Test Access Port) Controller Data Input is the serial
input for test instructions and data. It has a permanent weak pullup resistor.
TDO
TMRCLK2:0
TMRGATE2:0
O
H(Z)/H(Q)Note 2
R(Z)/R(Q)Note 2
I(Z)/I(Q)Note 2
P(Z)/ P(Q) Note 2
TAP (Test Access Port) Controller Data Output is the serial
output for test instructions and data.
I
Timer/Counter Clock Inputs can serve as external clock inputs
for the corresponding timer/counters. (The timer/counters can
also be clocked internally.) They are multiplexed as follows:
TMRCLK2 with PEREQ, TMRCLK1 with INT6, and TMRCLK0
with INT4. TMRCLK2 has a temporary weak pull-down resistor.
I
Timer/Counter Gate Inputs can control the corresponding
timer/counter’s counting (enable, disable, or trigger, depending
on the programmed mode). They are multiplexed as follows:
TMRGATE2 with BUSY#, TMRGATE1 with INT7, and
TMRGATE0 with INT5. TMRGATE2 has a temporary weak pullup resistor.
O
H(Q)
R(WH)
I(Q)
P(X)/P(Q)Note 1
Timer/Counter Outputs provide the output of the corresponding
timer/counter. The form of the output depends on the
programmed mode. They are multiplexed as follows: TMROUT2
with ERROR#, TMROUT1 with P3.1 and INT8, and TMROUT0
with P3.0 and INT9.
TMROUT1:0
O
H(Q)
R(WL)
I(Q)
P(X)/P(Q)Note 1
Timer/Counter Outputs provide the output of the corresponding
timer/counter. The form of the output depends on the
programmed mode. They are multiplexed as follows: TMROUT2
with ERROR#, TMROUT1 with P3.1 and INT8, and TMROUT0
with P3.0 and INT9.
TMS
I
TMROUT2
TAP (Test Access Port) Controller Mode Select controls the
sequence of the TAP controller’s states. It has a permanent
weak pull-up resistor.
NOTES:
1. X if clock source is internal; Q if clock source is external
2. Q if JTAG unit is shifting out data, Z if it is not
Datasheet
17
Intel386™ EX Embedded Microprocessor
Table 4.
Intel386™ EX Microprocessor Pin Descriptions (Sheet 6 of 6)
Symbol
Type
Output States
Name and Function
TAP (Test Access Port) Controller Reset resets the TAP
controller at power-up and each time it is activated. It has a
permanent weak pull-up resistor.
TRST#
ST
TXD1
O
H(Q)
R(1)
I(Q)
P(X)/P(Q)Note 1
Transmit Data SIO1 and SIO0 transmit serial data from the
individual serial channels. TXD1 is multiplexed with DACK1#,
and TXD0 is multiplexed with P2.6.
TXD0
O
H(Q)
R(WL)
I(Q)
P(X)/P(Q)Note 1
Transmit Data SIO1 and SIO0 transmit serial data from the
individual serial channels. TXD1 is multiplexed with DACK1#,
and TXD0 is multiplexed with P2.6.
UCS#
O
H(1)
R(0)
I(Q)
P(X)
VCC
P
System Power provides the nominal DC supply input. This pin is
connected externally to a VCC board plane.
VSS
G
System Ground provides the 0 V connection from which all
inputs and outputs are measured. This pin is connected
externally to a ground board plane.
WDTOUT
O
H(Q)
R(0)
I(Q)
P(X)
Watchdog Timer Output indicates that the watchdog timer has
expired.
W/R#
O
H(Z)
R(0)
I(1)
P(1)
Write/Read indicates whether the current bus cycle is a write
cycle or a read cycle. When W/R# is HIGH, the bus cycle is a
write cycle; when W/R# is LOW, the bus cycle is a read cycle.
WR#
O
H(1)
R(1)
I(1)
P(1)
Write Enable indicates that the current bus cycle is a write cycle.
Upper Chip-select is activated when the address of a memory
or I/O bus cycle is within the address region programmed by the
user.
NOTES:
1. X if clock source is internal; Q if clock source is external
2. Q if JTAG unit is shifting out data, Z if it is not
18
Datasheet
Intel386™ EX Embedded Microprocessor
4.0
Functional Description
The Intel386 EX microprocessor is a fully static, 32-bit processor optimized for embedded
applications. It features low power and low voltage capabilities, integration of many commonly
used DOS-type peripherals, and a 32-bit programming architecture compatible with the large
software base of Intel386 processors. The following sections provide an overview of the integrated
peripherals.
4.1
Clock Generation and Power Management Unit
The clock generation circuit includes a divide-by-two counter, a programmable divider for
generating a prescaled clock (PSCLK), a divide-by-two counter for generating baud-rate clock
inputs, and Reset circuitry. The CLK2 input provides the fundamental timing for the chip. It is
divided by two internally to generate a 50% duty cycle Phase1 (PH1) and Phase 2 (PH2) for the
core and integrated peripherals. For power management, separate clocks are routed to the core
(PH1C/PH2C) and the peripheral modules (PH1P/PH2P). To help synchronize with external
devices, the PH1P clock is provided on the CLKOUT output pin.
Two Power Management modes are provided for flexible power-saving options. During Idle mode,
the clocks to the CPU core are frozen in a known state (PH1C low and PH2C high), while the
clocks to the peripherals continue to toggle. In Powerdown mode, the clocks to both core and
peripherals are frozen in a known state (PH1C low and PH2C high). The Bus Interface Unit will
not honor any DMA, DRAM refresh, or HOLD requests in Powerdown mode because the clocks to
the entire device are frozen.
4.2
Chip-select Unit
The Chip-Select Unit (CSU) decodes bus cycle address and status information and enables the
appropriate chip-selects. The individual chip-selects become valid in the same bus state as the
address and become inactive when either a new address is selected or the current bus cycle is
complete.
The CSU is divided into eight separate chip-select regions, each of which can enable one of the
eight chip-select pins. Each chip-select region can be mapped into memory or I/O space. A
memory-mapped chip-select region can start on any 2(n+1) Kbyte address location (where n = 0–15,
depending upon the mask register). An I/O-mapped chip-select region can start on any 2(n+1) byte
address location (where n = 0–15, depending upon the mask register). The size of the region is also
dependent upon the mask used.
4.3
Interrupt Control Unit
The Intel386 EX processor’s Interrupt Control Unit (ICU) contains two 8259A modules connected
in a cascade mode. These modules are similar to the industry-standard 8259A architecture.
The Interrupt Control Unit directly supports up to ten external (INT9:0) and up to eight internal
interrupt request signals. Pending interrupt requests are posted in the Interrupt Request Registers,
which contain one bit for each interrupt request signal. When an interrupt request is asserted, the
corresponding Interrupt Request Register bit is set. The 8259A modules can be programmed to
Datasheet
19
Intel386™ EX Embedded Microprocessor
recognize either an active-high level or a positive transition on the interrupt request lines. An
internal Priority Resolver decides which pending interrupt request (if more than one exists) is the
highest priority, based on the programmed operating mode. The Priority Resolver controls the
single interrupt request line to the CPU. The Priority Resolver’s default priority scheme places the
master interrupt controller’s IR0 as the highest priority and the master’s IR7 as the lowest. The
priority can be modified through software.
Besides the ten interrupt request inputs available to the Intel386 EX microprocessor, additional
interrupts can be supported by cascaded external 8259A modules. Up to four external 8259A units
can be cascaded to the master through connections to the INT3:0 pins. In this configuration, the
interrupt acknowledge (INTA#) signal can be decoded externally using the ADS#, D/C#, W/R#,
and M/IO# signals.
4.4
Timer/Counter Unit
The Timer/Counter Unit (TCU) on the Intel386 EX microprocessor has the same basic
functionality as the industry-standard 82C54 counter/timer. The TCU provides three independent
16-bit counters, each capable of handling clock inputs up to 8 MHz. This maximum frequency
must be considered when programming the input clocks for the counters. Six programmable timer
modes allow the counters to be used as event counters, elapsed-time indicators, programmable oneshots, and in many other applications. All modes are software programmable.
4.5
Watchdog Timer Unit
The Watchdog Timer (WDT) unit consists of a 32-bit down-counter that decrements every PH1P
cycle, allowing up to 4.3 billion count intervals. The WDTOUT pin is driven high for sixteen
CLK2 cycles when the down-counter reaches zero (the WDT times out). The WDTOUT signal can
be used to reset the chip, to request an interrupt, or to indicate to the user that a ready-hang
situation has occurred. The down-counter can also be updated with a user-defined 32-bit reload
value under certain conditions. Alternatively, the WDT unit can be used as a bus monitor or as a
general-purpose timer.
4.6
Asynchronous Serial I/O Unit
The Intel386 EX microprocessor’s asynchronous Serial I/O (SIO) unit is a Universal
Asynchronous Receiver/ Transmitter (UART). Functionally, it is equivalent to the National
Semiconductor NS16450 and INS8250. The Intel386 EX embedded processor contains two fullduplex, asynchronous serial channels.
The SIO unit converts serial data characters received from a peripheral device or modem to parallel
data and converts parallel data characters received from the CPU to serial data. The CPU can read
the status of the serial port at any time during its operation. The status information includes the type
and condition of the transfer operations being performed and any errors (parity, framing, overrun,
or break interrupt).
20
Datasheet
Intel386™ EX Embedded Microprocessor
Each asynchronous serial channel includes full modem control support (CTS#, RTS#, DSR#,
DTR#, RI#, and DCD#) and is completely programmable. The programmable options include
character length (5, 6, 7, or 8 bits), stop bits (1, 1.5, or 2), and parity (even, odd, forced, or none). In
addition, it contains a programmable baud-rate generator capable of clock rates from 0 to 512
Kbaud.
4.7
Synchronous Serial I/O Unit
The Synchronous Serial I/O (SSIO) unit provides for simultaneous, bidirectional communications.
It consists of a transmit channel, a receive channel, and a dedicated baud-rate generator. The
transmit and receive channels can be operated independently (with different clocks) to provide
non-lockstep, full-duplex communications; either channel can originate the clocking signal (Master
Mode) or receive an externally generated clocking signal (Slave Mode).
The SSIO provides numerous features for ease and flexibility of operation. With a maximum clock
input of CLK2/4 to the baud-rate generator, the SSIO can deliver a baud rate of up to 8.25 Mbits
per second with a processor clock of 33 MHz. Each channel is double buffered. The two channels
share the baud-rate generator and a multiply-by-two transmit and receive clock. The SSIO supports
16-bit serial communications with independently enabled transmit and receive functions and gated
interrupt outputs to the interrupt controller.
4.8
Parallel I/O Unit
The Intel386 EX microprocessor has three 8-bit, general-purpose I/O ports. All port pins are
bidirectional, with TTL-level inputs and CMOS-level outputs. All pins have both a standard
operating mode and a peripheral mode (a multiplexed function), and all have similar sets of control
registers located in I/O address space.
4.9
DMA and Bus Arbiter Unit
The Intel386 EX microprocessor’s DMA controller is a two-channel DMA; each channel operates
independently of the other. Within the operation of the individual channels, several different data
transfer modes are available. These modes can be combined in various configurations to provide a
very versatile DMA controller. Its feature set has enhancements beyond the 8237 DMA family;
however, it can be configured such that it can be used in an 8237-like mode. Each channel can
transfer data between any combination of memory and I/O with any combination (8 or 16 bits) of
data path widths. An internal temporary register that can disassemble or assemble data to or from
either an aligned or a nonaligned destination or source optimizes bus bandwidth.
The bus arbiter, a part of the DMA controller, works much like the priority resolving circuitry of a
DMA. It receives service requests from the two DMA channels, the external bus master, and the
DRAM Refresh Control Unit. The bus arbiter requests bus ownership from the core and resolves
priority issues among all active requests when bus mastership is granted.
Each DMA channel consists of three major components: the Requestor, the Target, and the Byte
Count. These components are identified by the contents of programmable registers that define the
memory or I/O device being serviced by the DMA. The Requestor is the device that requires and
requests service from the DMA controller. Only the Requestor is considered capable of initializing
Datasheet
21
Intel386™ EX Embedded Microprocessor
or terminating a DMA process. The Target is the device with which the Requestor wishes to
communicate. The DMA process considers the Target a slave that is incapable of controlling the
process. The Byte Count dictates the amount of data that must be transferred.
4.10
Refresh Control Unit
The Refresh Control Unit (RCU) simplifies dynamic memory controller design with its integrated
address and clock counters. Integrating the RCU into the processor allows an external DRAM
controller to use chip-selects, wait state logic, and status lines.
The Refresh Control Unit:
•
•
•
•
Provides a programmable-interval timer
Provides the bus arbitration logic to gain control of the bus to run refresh cycles
Contains the logic to generate row addresses to refresh DRAM rows individually
Contains the logic to signal the start of a refresh cycle
The RCU contains a 13-bit address counter that forms the refresh address, supporting DRAMs with
up to 13 rows of memory cells (13 refresh address bits). This includes all practical DRAM sizes for
the Intel386 EX microprocessor’s 64 Mbyte address space.
4.11
JTAG Test-logic Unit
The JTAG Test-logic Unit provides access to the device pins and to a number of other testable areas
on the device. It is fully compliant with the IEEE 1149.1 standard and thus interfaces with five
dedicated pins: TRST#, TCK, TMS, TDI, and TDO. It contains the Test Access Port (TAP) finitestate machine, a 4-bit instruction register, a 32-bit identification register, and a single-bit bypass
register. The test-logic unit also contains the necessary logic to generate clock and control signals
for the Boundary Scan chain.
Since the test-logic unit has its own clock and reset signals, it can operate autonomously. While the
rest of the microprocessor is in Reset or Powerdown, the JTAG unit can read or write various
register chains.
22
Datasheet
Intel386™ EX Embedded Microprocessor
5.0
Design Considerations
This section describes the Intel386 EX microprocessor’s instruction set and its component and
revision identifiers.
5.1
Instruction Set
The Intel386 EX microprocessor uses the same instruction set as the Intel386 SX microprocessor
with the following exceptions.
The Intel386 EX microprocessor has one new instruction (RSM). This Resume instruction causes
the processor to exit System Management Mode (SMM). RSM requires 338 clocks per instruction
(CPI).
The Intel386 EX microprocessor requires more clock cycles than the Intel386 SX microprocessor
to execute some instructions. Table 5 lists these instructions and the Intel386 EX microprocessor
clock count. For the equivalent Intel386 SX microprocessor clock count, refer to the “Instruction
Set Clock Count Summary” table in the Intel386™ SX Microprocessor datasheet (order number
240187).
Table 5.
Microprocessor Clocks Per Instruction
Clock Count
Instruction
Virtual 8086 Mode(2)
POPA
(1)
Real Address Mode
or Virtual 8086 Mode
Protected Virtual Address Mode(3)
29
35
IN:
Fixed Port
Variable Port
27
28
14
15
8/29
9/29
OUT:
Fixed Port
Variable Port
27
28
14
15
8/29
9/29
INS
30
17
10/32
OUTS
31
18
11/33
REP INS
31+6n (Note 4)
17+7n (Note 4)
11+7n/32+6n (Note 4)
REP OUTS
30+8n (Note 4)
16+8n (Note 4)
10+8n/31+8n (Note 4)
HLT
7
7
MOV CR0, reg
10
10
NOTES:
1. For IN, OUT, INS, OUTS, REP INS, and REP OUTS instructions, add one clock count for each wait state
generated by the peripheral being accessed (the values in the table are for zero wait state).
2. The clock count values in this column apply if I/O permission allows I/O to the port in virtual 8086 mode. If
the I/O bit map denies permission, exception fault 13 occurs; see clock counts for the INT 3 instruction in
the “Instruction Set Clock Count Summary” table in the Intel386™ SX Microprocessor datasheet (order
number 240187).
3. When two clock counts are listed, the smaller value refers to the case where CPL ≤ IOPL and the larger
value refers to the case where CPL>IOPL. CPL is the current privilege level, and IOPL is the I/O privilege
level.
4. n = the number of times repeated.
Datasheet
23
Intel386™ EX Embedded Microprocessor
5.2
Component and Revision Identifiers
To assist users, the microprocessor holds a component identifier and revision identifier in its DX
register after reset. The upper 8 bits of DX hold the component identifier, 23H. (The lower nibble,
3H, identifies the Intel386 architecture, while the upper nibble, 2H, identifies the second member
of the Intel386 microprocessor family.)
The lower 8 bits of DX hold the revision level identifier. The revision identifier will, in general,
chronologically track those component steppings that are intended to have certain improvements or
distinction from previous steppings. The revision identifier will track that of the Intel386 CPU
whenever possible. However, the revision identifier value is not guaranteed to change with every
stepping revision or to follow a completely uniform numerical sequence, depending on the type or
intent of the revision or the manufacturing materials required to be changed. Intel has sole
discretion over these characteristics of the component. The initial revision identifier for the
Intel386 EX microprocessor is 09H.
5.3
Package Thermal Specifications
The Intel386 EX microprocessor is specified for operation with a minimum case temperature
(TCASE(MIN)) of -40° C and a maximum case temperature (TCASE(MAX)) dependent on power
dissipation (see Figures 4 through 7). The case temperature can be measured in any environment to
determine whether the microprocessor is within the specified operating range. The case
temperature should be measured at the center of the top surface opposite the pins.
An increase in the ambient temperature (TA) causes a proportional increase in the case temperature
(TCASE) and the junction temperature (TJ), which is the junction temperature on the die itself. A
packaged device produces thermal resistance between junction and case temperatures (θJC) and
between junction and ambient temperatures (θJA). The relationships between the temperature and
thermal resistance parameters are expressed by these equations:
TJ = TCASE + P × θJC
TA = TJ – P × θJA
TCASE = TA + P × [θJA – θJC]
P = power dissipated as heat = V CC × ICC
A safe operating temperature can be calculated from the above equations by using the maximum
safe TJ of 120° C, the power drawn by the chip in the specific design, and the θJC value from Table
6. The θJA value depends on the airflow (measured at the top of the chip) provided by the system
ventilation, board layout, board thickness, and potentially other factors in the design of the
application. The θJA values are given for reference only and are not guaranteed.
Table 6.
Thermal Resistances (0°C/W) θJA, θJC
Package
θJA vs. Airflow (ft/min)
θJC
0
100
200
132 PQFP
7
28
24
22
144 TQFP
4
36
31
27
Figures 4 through 7 provide maximum case temperature as a function of frequency.
24
Datasheet
Intel386™ EX Embedded Microprocessor
Figure 4. Maximum Case Temperature vs. Frequency for Typical Power Values
(132-lead PQFP, VCC = 5.5 V)
113.9
114
132 Lead PQFP
113
112.25
112
111
Tc
(deg C)
110.7
110
109
108
107.8
107
16
20
25
33
Operating Frequency (MHz)
A3346-02
Figure 5. Maximum Case Temperature vs. Frequency for Typical Power Values
(144-lead TQFP, V CC = 5.5 V nominal)
116
115
114.9
144 Lead TQFP
114
113.5
113
112.25
Tc
112
(deg C)
111
109.8
110
109
108
16
20
25
33
Operating Frequency (MHz)
A3347-02
Datasheet
25
Intel386™ EX Embedded Microprocessor
Figure 6. Maximum Case Temperature vs. Frequency for Typical Power Values
(132-lead PQFP, V CC = 3.6 V)
117.5
117.5
132 Lead PQFP
117.0
Tc
(deg C)
117.0
116.5
116.5
16
20
25
Operating Frequency (MHz)
A3348-02
Figure 7. Maximum Case Temperature vs. Frequency for Typical Power Values
(144-lead TQFP, V CC = 3.6 V)
118.0
118.0
144 Lead TQFP
117.5
117.5
Tc
(deg C)
117.0
117.0
16
20
25
Operating Frequency (MHz)
A3349-01
26
Datasheet
Intel386™ EX Embedded Microprocessor
6.0
Electrical Specifications
6.1
Maximum Ratings
Warning:
Stressing the device beyond the “Maximum Ratings” may cause permanent damage. These are
stress ratings only.
Table 7.
5 V Intel386 EXTC Processor Maximum Ratings
Parameter
Storage Temperature
Supply Voltage with Respect to VSS
Voltage on Other Pins
VCC (Digital Supply Voltage)
Maximum Rating
–65°C to +150°C
–0.5 V to 6.5 V
–0.5 V to VCC + 0.5 V
4.5 V to 5.5 V
TCASE (Case Temperature Under Bias)
TCASE(MIN)
TCASE(MAX)
-40°C
(see Figures 4 and 5)
FOSC (Operating Frequency)
Table 8.
0 MHz to 33 MHz
3 V Intel386 EXTB Processor Maximum Ratings
Parameter
Storage Temperature
Supply Voltage with Respect to VSS
Voltage on Other Pins
VCC (Digital Supply Voltage)
Maximum Rating
–65°C to +150°C
–0.5 V to 4.6 V
–0.5 V to VCC + 0.5 V
20 MHz — 2.7 V to 3.6 V
25 MHz — 3.0 V to 3.6 V
TCASE (Case Temperature Under Bias)
TCASE(MIN)
TCASE(MAX)
FOSC (Operating Frequency)
Datasheet
-40°C
(see Figures 6 and 7)
0 MHz to 25 MHz
27
Intel386™ EX Embedded Microprocessor
6.2
Table 9.
DC Specifications
5-Volt DC Characteristics
Symbol
Parameter
Min.
Max.
Unit
Test Condition
V IL
Input Low Voltage for all input pins
except CLK2, TRST#, RESET,
SMI#, and NMI
–0.3
0.8
V
VIH
Input High Voltage for all input pins
except CLK2, TRST#, RESET,
SMI#, and NMI
2.0
VCC + 0.3
V
VILC
Input Low Voltage for CLK2,
TRST#, RESET, SMI#, and NMI
-0.3
0.8
V
VIHC
Input High Voltage for CLK2,
TRST#, RESET, SMI#, and NMI
V CC-0.8
VCC+0.3
V
0.45
0.45
V
V
IOL = 8 mA
IOL = 16 mA
V
V
V
IOH = –0.2 mA
IOH = –8 mA
IOH = –16 mA
V
IOL = 2 mA
V
IOH = –0.2 mA
IOH = –2 mA
µA
0 ≤ VIN ≤ VCC
FLT# is not tested for ILI
Output Low Voltage
VOL
28
All pins except Port 3
Port 3
VOH
Output High Voltage
All output pins
All pins except Port 3
Port 3 pins (2 max)
VOLC
CLKOUT
VOHC
CLKOUT
ILI
Input Leakage Current
ILO
Output Leakage Current
V CC-0.5
2.45
2.45
0.45
V CC-0.5
2.45
±15
±15
µA
0.45V ≤ VOUT ≤ VCC
320
250
mA
mA
FOSC =33 MHz
FOSC =25 MHz
(tested with device held in
reset, inputs held in their
inactive state)
FOSC =33 MHz
FOSC =25 MHz
ICC
Supply Current
IIDLE
Idle Mode Current
110
85
mA
mA
IPD
Powerdown Current
100
µA
CS
Pin Capacitance (any pin to VSS)
10
pF
Not tested
Datasheet
Intel386™ EX Embedded Microprocessor
Table 10. 3-Volt DC Characteristics
Symbol
Parameter
Max.
Unit
Test Condition
VIL
Input Low Voltage for all
input pins except CLK2,
TRST#, RESET, SMI#, and
NMI
–0.3
0.8
V
VIH
Input High Voltage for all
input pins except CLK2,
TRST#, RESET, SMI#, and
NMI
2.0
V CC + 0.3
V
VILC
Input Low Voltage for CLK2,
TRST#, RESET, SMI#, and
NMI
-0.3
0.8
V
VIHC
Input High Voltage for CLK2,
TRST#, RESET, SMI#, and
NMI
VCC -0.6
VCC+0.3
V
Output Low Voltage
0.20
V
IOL = 100 µA, 2.7 V ≤ V CC ≤ 3.6 V
(LVCMOS)
All pins except Port 3
Port 3 pins (2 max)
0.45
0.45
V
V
IOL = 4mA, 3.0 V≤VCC≤3.6 V (LVTTL)
IOL = 8mA, 3.0 V≤VCC≤3.6 V (LVTTL)
VCC -0.2
V
VCC -0.65
V
IOH= -100 µA, 2.7 V≤VCC ≤3.6 V
(LVCMOS)
IOH= -4mA, 3.0 V≤VCC ≤3.6V (LVTTL)
VCC -0.65
V
IOH= -8mA, 3.0 V≤VCC ≤3.6V (LVTTL)
V
IOL = 100 µA, 2.7 V ≤ V CC ≤ 3.6 V
IOL = 1 mA, 3.0 V ≤ VCC ≤ 3.6 V
(LVTTL)
V
IOH = -100 µA, 2.7 V ≤ VCC ≤ 3.6 V
IOH = -1 mA, 3.0 V ≤ VCC ≤ 3.6 V
(LVTTL)
µA
0 ≤ VIN ≤ VCC
FLT# is not tested for ILI
±15
µA
0.45V ≤ VOUT ≤ VCC
140
110
mA
mA
FOSC = 25 MHz, VCC=3.6 V
FOSC = 20 MHz, VCC=3.6 V
VOL
Output High Voltage
VOH
Datasheet
Min.
All pins except Port 3
Port 3
VOLC
CLKOUT
VOHC
CLKOUT
ILI
Input Leakage Current
ILO
Output Leakage Current
0.2
0.45
VCC -0.2
VCC -0.65
±5
ICC
Supply Current
IIDLE
Idle Mode Current
50
40
mA
mA
IPD
Powerdown Current
100
µA
CS
Pin Capacitance (any pin to
V SS)
10
pF
(tested with device held in reset,
inputs held in their inactive state)
FOSC = 25 MHz, VCC=3.6 V
FOSC = 20 MHz, VCC=3.6 V
Not tested
29
Intel386™ EX Embedded Microprocessor
6.3
AC Specifications
Table 11 lists output delays, input setup requirements, and input hold requirements for the 5 V
EXTC processor; Table 12 is for the EXTB processor. All AC specifications are relative to the
CLK2 rising edge crossing the VCC/2 level for the EXTB, or 2.0 Volts for the EXTC.
Figures 8 and 9 show the measurement points for AC specifications for the EXTB and EXTC
processors. Inputs must be driven to the indicated voltage levels when AC specifications are
measured. Output delays are specified with minimum and maximum limits measured as shown.
The minimum delay times are hold times provided to external circuitry. Input setup and hold times
are specified as minimums, defining the smallest acceptable sampling window. Within the
sampling window, a synchronous input signal must be stable for correct operation.
Outputs ADS#, W/R#, CS5:0#, UCS#, D/C#, M/IO#, LOCK#, BHE#, BLE#, REFRESH#/CS6#,
READY#, LBA#, A25:1, HLDA and SMIACT# change only at the beginning of phase one. D15:0
(write cycles) and PWRDOWN change only at the beginning of phase two. RD# and WR# change
to their active states at the beginning of phase two. RD# changes to its inactive state (end of cycle)
at the beginning of phase one. See the Intel386™ EX Embedded Microprocessor User's Manual for
a detailed explanation of early READY# vs. late READY#.
The READY#, HOLD, BUSY#, ERROR#, PEREQ, BS8#, and D15:0 (read cycles) inputs are
sampled at the beginning of phase one. The NA#, SMI#, and NMI inputs are sampled at the
beginning of phase two.
Figure 8. Drive Levels and Measurement Points for AC Specifications (EXTC)
Tx
PH1
CLK2
PH2
b
A
OUTPUTS
(A25:1,BHE#
BLE#,ADS#,M/IO#
D/C#W/R#,LOCK#
HLDA, SMIACT#)
B
Min
Valid
a
Output n
Max
a Valid
Output n+1
A
B
Min
Valid
a
Output n
OUTPUTS
(D15:0)
C
INPUTS
(N/A#,INTR
NMI,SMI#)
3.0V
INPUTS
(READY#,HOLD
FLT#,ERROR#
BUSY#,PEREQ
D15:0,A20)
0V
c
Max
a Valid
Output n+1
D
Valid
Input
c
C
3.0V
0V
c
D
Valid
Input
c
LEGEND
a - VCC /2
b - 2.0V
c = 1.5V
A - Maximum Output Delay Spec
B - Minimum Output Delay Spec
C - Minimum Input Setup Spec
D - Minimum Input Hold Spec
30
Datasheet
Intel386™ EX Embedded Microprocessor
Figure 9. Drive Levels and Measurement Points for AC Specifications (EXTB)
Tx
PH1
CLK2
PH2
a
A
OUTPUTS
(A25:1,BHE#
BLE#,ADS#,M/IO#
D/C#W/R#,LOCK#
HLDA, SMIACT#)
B
Min
Valid
a
Output n
Max
a Valid
Output n+1
A
B
Min
Valid
a
Output n
OUTPUTS
(D15:0)
C
INPUTS
(N/A#,INTR
NMI,SMI#)
2.0V
INPUTS
(READY#,HOLD
FLT#,ERROR#
BUSY#,PEREQ
D15:0,A20)
0V
b
Max
a Valid
Output n+1
D
Valid
Input
b
C
2.0V
0V
b
D
Valid
Input
b
LEGEND
a - VCC/2
b = 1.5V
A - Maximum Output Delay Spec
B - Minimum Output Delay Spec
C - Minimum Input Setup Spec
D - Minimum Input Hold Spec
A2600-02
Datasheet
31
Intel386™ EX Embedded Microprocessor
Table 11. 5-Volt AC Characteristics (Sheet 1 of 5)
33 MHz
Symbol
Parameter
Operating Frequency
t1
CLK2 Period
t2a
CLK2 High Time
t2b
t3a
25 MHz
Min.
(ns)
Max.
(ns)
Min.
(ns)
Max.
(ns)
0
33
0
25
Test Condition
one-half CLK2 frequency
in MHz (1)
15
20
6.25
7
(2)
CLK2 High Time
4
4
(2)
CLK2 Low Time
6.25
7
(2)
t3b
CLK2 Low Time
4.5
t4
CLK2 Fall Time
t5
CLK2 Rise Time
t6
A25:1 Valid Delay
5
4
4
4
21
4
(2)
7
(2)
7
(2)
24
CL = 50 pF
t7
A25:1 Float Delay
4
28
4
28
(3)
t8
BHE#, BLE#, LOCK# Valid Delay
4
21
4
24
CL = 50 pF
t8a
SMIACT# Valid Delay
4
21
4
24
CL = 50 pF
t9
BHE#, BLE#, LOCK# Float Delay
4
28
4
28
(3)
t10
M/IO#, D/C#, W/R#, ADS#,
REFRESH# Valid Delay
4
21
4
24
CL = 50 pF
t10a
RD#, WR# Valid Delay
4
18
4
22
t10b
WR# Valid Delay for the rising
edge with respect to phase two
(external late READY#)
4
28
4
28
(6)
t11
M/IO#, D/C#, W/R#, REFRESH#,
ADS# Float Delay
4
28
4
28
(3)
t12
D15:0 Write Data Valid Delay
4
23
4
23
CL = 50 pF
t13
D15:0 Write Data Float delay
4
22
4
22
(3)
t14
HLDA Valid Delay
4
18
4
22
CL = 50 pF
t15
NA# Setup Time
5
t16
NA# Hold Time
3
3
t19
READY# Setup Time
8
9
t19a
BS8# Setup Time
11
11
5
NOTE:
1. Tested at maximum operating frequency and guaranteed by design characterization at lower operating
frequencies.
2. These are not tested. They are guaranteed by characterization.
3. Float condition occurs when maximum output current becomes less than ILO in magnitude. Float delay is not
fully tested.
4. These inputs may be asynchronous to CLK2. The setup and hold specifications are given to ensure recognition
within a specific CLK2 period.
5. These specifications are for information only and are not tested. They are intended to assist the designer in
selecting memory speeds. For each wait state in the design add two CLK2 cycles to the specification.
6. This specification assumes that READY# goes active after the rising edge of phase 2, so that WR# goes
inactive as a result of READY# falling.
7. This specification assumes that READY# goes active before the rising edge of phase 2, so that WR# goes
inactive as a result of phase 2 rising.
8. This specification applies if READY# is generated internally.
32
Datasheet
Intel386™ EX Embedded Microprocessor
Table 11. 5-Volt AC Characteristics (Sheet 2 of 5)
33 MHz
Symbol
Parameter
Min.
(ns)
25 MHz
Max.
(ns)
Min.
(ns)
Test Condition
Max.
(ns)
t20
READY#, BS8# Hold Time
4
4
t21
D15:0 Read Setup Time
7
7
t22
D15:0 Read Hold Time
4
4
t23
HOLD Setup Time
8
8
t24
HOLD Hold Time
3
3
t25
RESET Setup Time
5
5
t26
RESET Hold Time
2
3
t27
NMI Setup Time
6
6
t27a
SMI# Setup Time
6
6
(4)
t28
NMI Hold Time
6
6
(4)
t28a
SMI# Hold Time
6
6
(4)
t29
PEREQ, ERROR#, BUSY# Setup
Time
6
6
(4)
t30
PEREQ, ERROR#, BUSY# Hold
Time
5
5
(4)
t31
READY# Valid Delay
4
24
4
26
t32
READY# Float Delay
4
34
4
34
t33
LBA# Valid Delay
4
20
4
22
4
30
CL = 30 pF
CL = 30 pF
(4)
t34
CS6:0#, UCS# Valid Delay
4
24 (25 in
SMM)
t35
CLKOUT Valid Delay
2
9
2
14
t36
PWRDOWN Valid Delay
4
15
4
18
t41
A25:1, BHE#, BLE# Valid to WR#
Low
0
0
t41a
UCS#, CS6:0# Valid to WR# Low
0
0
t42
A25:1, BHE#, BLE# Hold After
WR# High
0
0
t42a
UCS#, CS6:0# Hold after WR#
High
0
0
t42b
A25:1. BHE#, BLE# Hold After
WR# High
10
10
CL = 30 pF
(6)
(7, 8)
NOTE:
1. Tested at maximum operating frequency and guaranteed by design characterization at lower operating
frequencies.
2. These are not tested. They are guaranteed by characterization.
3. Float condition occurs when maximum output current becomes less than ILO in magnitude. Float delay is not
fully tested.
4. These inputs may be asynchronous to CLK2. The setup and hold specifications are given to ensure recognition
within a specific CLK2 period.
5. These specifications are for information only and are not tested. They are intended to assist the designer in
selecting memory speeds. For each wait state in the design add two CLK2 cycles to the specification.
6. This specification assumes that READY# goes active after the rising edge of phase 2, so that WR# goes
inactive as a result of READY# falling.
7. This specification assumes that READY# goes active before the rising edge of phase 2, so that WR# goes
inactive as a result of phase 2 rising.
8. This specification applies if READY# is generated internally.
Datasheet
33
Intel386™ EX Embedded Microprocessor
Table 11. 5-Volt AC Characteristics (Sheet 3 of 5)
33 MHz
Symbol
Parameter
Min.
(ns)
Max.
(ns)
25 MHz
Min.
(ns)
Test Condition
Max.
(ns)
t43
D15:0 Output Valid to WR# High
2CLK2
–10
2CLK2
– 10
t44
D15:0 Output Hold After WR# High
CLK2
–10
CLK2
–10
t45
WR# High to D15:0 Float
t46
WR# Pulse Width
t47
A25:1, BHE#, BLE# Valid to D15:0
Valid
4CLK2 28
4CLK2(5)
31
t47a
UCS#, CS6:0# Valid to D15-D0
Valid
4CLK2 31
4CLK2 (5)
35
t48
RD# Low to D15:0 Input Valid
3CLK2 –
25
3CLK2 –
(5)
29
t49
D15:0 Hold After RD# High
t50
RD# High to D15:0 Float
t51
A25:1, BHE#, BLE# Hold After
RD# High
0
0
t51a
UCS#, CS6:0# Hold after RD#
High
0
0
t52
RD# Pulse Width
3CLK2
–10
3CLK2
–10
CLK2
CLK2
+ 10
2CLK2
–10
(5)
+ 10
2CLK2
–10
0
(3)
(7)
0
CLK2
CLK2
(3)
Synchronous Serial I/O (SSIO) Unit
t100
STXCLK, SRXCLK Frequency
(Master Mode)
CLK2/8
CLK2/8 (Unit is MHz)
t101
STXCLK, SRXCLK Frequency
(Slave Mode)
CLK2/8
CLK2/8 (Unit is MHz)
t102
STXCLK, SRXCLK Low Time
7CLK2/2
t103
STXCLK, SRXCLK High Time
7CLK2/2
t104
STXCLK Low to SSIOTX Delay
t105
SSIORX to SRXCLK High Setup
Time
t106
SSIORX from SRXCLK Hold Time
7CLK2/2
(2)
7CLK2/2
3CLK2
(2)
3CLK2
0
0
3CLK2
3CLK2
(2)
NOTE:
1. Tested at maximum operating frequency and guaranteed by design characterization at lower operating
frequencies.
2. These are not tested. They are guaranteed by characterization.
3. Float condition occurs when maximum output current becomes less than ILO in magnitude. Float delay is not
fully tested.
4. These inputs may be asynchronous to CLK2. The setup and hold specifications are given to ensure recognition
within a specific CLK2 period.
5. These specifications are for information only and are not tested. They are intended to assist the designer in
selecting memory speeds. For each wait state in the design add two CLK2 cycles to the specification.
6. This specification assumes that READY# goes active after the rising edge of phase 2, so that WR# goes
inactive as a result of READY# falling.
7. This specification assumes that READY# goes active before the rising edge of phase 2, so that WR# goes
inactive as a result of phase 2 rising.
8. This specification applies if READY# is generated internally.
34
Datasheet
Intel386™ EX Embedded Microprocessor
Table 11. 5-Volt AC Characteristics (Sheet 4 of 5)
33 MHz
Symbol
Parameter
Min.
(ns)
25 MHz
Max.
(ns)
Min.
(ns)
Test Condition
Max.
(ns)
Timer Control Unit (TCU) Inputs
t107
TMRCLKn Frequency
t108
TMRCLKn Low
60
60
t109
TMRCLKn High
60
60
8
8
t110
TMRGATEn High Width
50
50
t111
TMRGATEn Low Width
50
50
t112
TMRGATEn to TMRCLK Setup
Time (external TMRCLK only)
10
10
t112a
TMRGATEn to TMRCLK Hold
Time (external TMRCLK only)
11
11
(Unit is MHz)
Timer Control Unit (TCU) Outputs
t113
TMRGATEn Low to TMROUT
Valid
29
32
t114
TMRCLKn Low to TMROUT Valid
29
32
Interrupt Control Unit (ICU) Inputs
t115
D7:0 Setup Time
(INTA# Cycle 2)
7
7
t116
D7:0 Hold Time
(INTA# Cycle 2)
4
4
Interrupt Control Unit (ICU) Outputs
t117
CLK2 High to CAS2:0 Valid
25
28
DMA Unit Inputs
t118
t119
t120
t121
DREQ Setup Time
(Sync Mode)
DREQ Hold Time
(Sync Mode)
DREQ Setup Time
(Async Mode)
DREQ Hold Time
(Async Mode)
15
15
4
4
9
9
9
9
(2)
(2)
NOTE:
1. Tested at maximum operating frequency and guaranteed by design characterization at lower operating
frequencies.
2. These are not tested. They are guaranteed by characterization.
3. Float condition occurs when maximum output current becomes less than ILO in magnitude. Float delay is not
fully tested.
4. These inputs may be asynchronous to CLK2. The setup and hold specifications are given to ensure recognition
within a specific CLK2 period.
5. These specifications are for information only and are not tested. They are intended to assist the designer in
selecting memory speeds. For each wait state in the design add two CLK2 cycles to the specification.
6. This specification assumes that READY# goes active after the rising edge of phase 2, so that WR# goes
inactive as a result of READY# falling.
7. This specification assumes that READY# goes active before the rising edge of phase 2, so that WR# goes
inactive as a result of phase 2 rising.
8. This specification applies if READY# is generated internally.
Datasheet
35
Intel386™ EX Embedded Microprocessor
Table 11. 5-Volt AC Characteristics (Sheet 5 of 5)
33 MHz
Symbol
t122
t123
t124
t125
Parameter
EOP# Setup Time
(Sync Mode)
EOP# Hold Time
(Sync Mode)
EOP# Setup Time
(Async Mode)
EOP# Hold Time
(Async Mode)
Min.
(ns)
25 MHz
Max.
(ns)
Min.
(ns)
15
15
4
4
9
9
9
9
Test Condition
Max.
(ns)
DMA Unit Outputs
t126
DACK# Output Valid Delay
4
21
4
25
t127
EOP# Active Delay
4
25
4
25
t128
EOP# Float Delay
4
25
4
25
(3)
10
(Unit is MHz)
JTAG Test-logic Unit
t129
TCK Frequency
10
NOTE:
1. Tested at maximum operating frequency and guaranteed by design characterization at lower operating
frequencies.
2. These are not tested. They are guaranteed by characterization.
3. Float condition occurs when maximum output current becomes less than ILO in magnitude. Float delay is not
fully tested.
4. These inputs may be asynchronous to CLK2. The setup and hold specifications are given to ensure recognition
within a specific CLK2 period.
5. These specifications are for information only and are not tested. They are intended to assist the designer in
selecting memory speeds. For each wait state in the design add two CLK2 cycles to the specification.
6. This specification assumes that READY# goes active after the rising edge of phase 2, so that WR# goes
inactive as a result of READY# falling.
7. This specification assumes that READY# goes active before the rising edge of phase 2, so that WR# goes
inactive as a result of phase 2 rising.
8. This specification applies if READY# is generated internally.
36
Datasheet
Intel386™ EX Embedded Microprocessor
Table 12. 3-Volt AC Characteristics (Sheet 1 of 5)
25 MHz
3.0 V to 3.6 V
Symbol
20 MHz
2.7 V to 3.6 V
Parameter
Test Condition
Min.
(ns)
Max.
(ns)
Min.
(ns)
Max.
(ns)
Operating Frequency
0
25
0
20
one-half CLK2 frequency
in MHz(1)
t1
CLK2 Period
20
25
t2a
CLK2 High Time
7
8
t2b
CLK2 High Time
4
5
(2)
t3a
CLK2 Low Time
7
8
(2)
t3b
CLK2 Low Time
5
t4
CLK2 Fall Time
t5
CLK2 Rise Time
8
(2)
t6
A25:1 Valid Delay
4
32
4
36
CL = 50 pF
t7
A25:1 Float Delay
4
29
4
36
(3)
t8
BHE#, BLE#, LOCK# Valid
Delay
4
32
4
34
CL = 50 pF
t8a
SMIACT# Valid Delay
4
32
4
34
CL = 50 pF
t9
BHE#, BLE#, LOCK# Float
Delay
4
23
4
32
(3)
t10
M/IO#, D/C#, W/R#, ADS#,
REFRESH# Valid Delay
4
32
4
34
CL = 50 pF
t10a
RD#, WR# Valid Delay
4
30
4
32
t10b
WR# Valid Delay for the rising
edge with respect to phase
two (external late READY#)
4
37
4
37
(6)
t11
M/IO#, D/C#, W/R#,
REFRESH#, ADS# Float
Delay
4
30
4
34
(3)
t12
D15:0 Write Data Valid Delay
4
31
4
34
CL = 50 pF
t13
D15:0 Write Data Float delay
4
20
4
28
(3)
t14
HLDA Valid Delay
4
30
4
32
CL = 50 pF
t15
NA# Setup Time
9
9
t16
NA# Hold Time
12
15
(2)
6
7
(2)
8
7
(2)
NOTE:
1. Tested at maximum operating frequency and guaranteed by design characterization at lower operating
frequencies.
2. These are not tested. They are guaranteed by characterization.
3. Float condition occurs when maximum output current becomes less than ILO in magnitude. Float delay is not
fully tested.
4. These inputs may be asynchronous to CLK2. The setup and hold specifications are given to ensure
recognition within a specific CLK2 period.
5. These specifications are for information only and are not tested. They are intended to assist the designer in
selecting memory speeds. For each wait state in the design add two CLK2 cycles to the specification.
6. This specification assumes that READY# goes active after the rising edge of phase 2, so that WR# goes
inactive as a result of READY# falling.
7. This specification assumes that READY# goes active before the rising edge of phase 2, so that WR# goes
inactive as a result of phase 2 rising.
8. This specification applies if READY# is generated internally.
Datasheet
37
Intel386™ EX Embedded Microprocessor
Table 12. 3-Volt AC Characteristics (Sheet 2 of 5)
25 MHz
3.0 V to 3.6 V
Symbol
20 MHz
2.7 V to 3.6 V
Test Condition
Parameter
Min.
(ns)
Max.
(ns)
Min.
(ns)
Max.
(ns)
t19
READY# Setup Time
15
17
t19a
BS8# Setup Time
17
19
t20
READY#, BS8# Hold Time
4
4
t21
D15:0 Read Setup Time
9
11
t22
D15:0 Read Hold Time
6
6
t23
HOLD Setup Time
17
22
t24
HOLD Hold Time
5
5
t25
RESET Setup Time
12
13
t26
RESET Hold Time
4
4
t27
NMI Setup Time
16
16
(4)
t27a
SMI# Setup Time
16
16
(4)
t28
NMI Hold Time
16
16
(4)
t28a
SMI# Hold Time
16
16
(4)
t29
PEREQ, ERROR#, BUSY#
Setup Time
14
16
(4)
t30
PEREQ, ERROR#, BUSY#
Hold Time
5
5
(4)
t31
READY# Valid Delay
4
33
4
42
CL = 30 pF
t32
READY# Float Delay
4
33
4
42
t33
LBA# Valid Delay
4
31
4
40
t34
CS6:0#, UCS# Valid Delay
4
33 (34 in
SMM)
4
42
CL = 30 pF
t35
CLKOUT Valid Delay
4
14
4
18
CL = 30 pF
t36
PWRDOWN Valid Delay
4
26
4
29
t41
A25:1, BHE#, BLE# Valid to
WR# Low
0
0
t41a
UCS#, CS6:0# Valid to WR#
Low
0
0
t42
A25:1, BHE#, BLE# Hold
After WR# High
0
0
(6)
NOTE:
1. Tested at maximum operating frequency and guaranteed by design characterization at lower operating
frequencies.
2. These are not tested. They are guaranteed by characterization.
3. Float condition occurs when maximum output current becomes less than ILO in magnitude. Float delay is not
fully tested.
4. These inputs may be asynchronous to CLK2. The setup and hold specifications are given to ensure
recognition within a specific CLK2 period.
5. These specifications are for information only and are not tested. They are intended to assist the designer in
selecting memory speeds. For each wait state in the design add two CLK2 cycles to the specification.
6. This specification assumes that READY# goes active after the rising edge of phase 2, so that WR# goes
inactive as a result of READY# falling.
7. This specification assumes that READY# goes active before the rising edge of phase 2, so that WR# goes
inactive as a result of phase 2 rising.
8. This specification applies if READY# is generated internally.
38
Datasheet
Intel386™ EX Embedded Microprocessor
Table 12. 3-Volt AC Characteristics (Sheet 3 of 5)
25 MHz
3.0 V to 3.6 V
Symbol
20 MHz
2.7 V to 3.6 V
Test Condition
Parameter
Min.
(ns)
Max.
(ns)
Min.
(ns)
Max.
(ns)
t42a
UCS#, CS6:0# Hold after
WR# High
0
0
t42b
A25:1. BHE#, BLE# Hold
After WR# High
10
10
t43
D15:0 Output Valid to WR#
High
2CLK2
– 10
2CLK2
– 10
t44
D15:0 Output Hold After WR#
High
CLK2
–10
CLK2
–10
t45
WR# High to D15:0 Float
t46
WR# Pulse Width
t47
A25:1, BHE#, BLE# Valid to
D15:0 Valid
4CLK241
4CLK2
- 45
(5)
t47a
UCS#, CS6:0# Valid to D15D0 Valid
4CLK2 42
4CLK2
- 53
(5)
t48
RD# Low to D15:0 Input Valid
3CLK2 –
39
3CLK2
– 43
(5)
CLK2
(3)
CLK2
(5)
CLK2
+10
+ 10
2CLK2
–10
(7, 8)
2CLK2
–10
t49
D15:0 Hold After RD# High
t50
RD# High to D15:0 Float
t51
A25:1, BHE#, BLE# Hold
After RD# High
0
0
t51a
UCS#, CS6:0# Hold after
RD# High
0
0
t52
RD# Pulse Width
3CLK2
–13
3CLK2
–15
0
(3)
(7)
0
CLK2
Synchronous Serial I/O (SSIO) Unit
t100
STXCLK, SRXCLK
Frequency (Master Mode)
CLK2/8
CLK2/8
(Unit is MHz)
t101
STXCLK, SRXCLK
Frequency (Slave Mode)
CLK2/8
CLK2/8
(Unit is MHz)
t102
STXCLK, SRXCLK Low Time
7CLK2/
2
7CLK2/
2
(2)
NOTE:
1. Tested at maximum operating frequency and guaranteed by design characterization at lower operating
frequencies.
2. These are not tested. They are guaranteed by characterization.
3. Float condition occurs when maximum output current becomes less than ILO in magnitude. Float delay is not
fully tested.
4. These inputs may be asynchronous to CLK2. The setup and hold specifications are given to ensure
recognition within a specific CLK2 period.
5. These specifications are for information only and are not tested. They are intended to assist the designer in
selecting memory speeds. For each wait state in the design add two CLK2 cycles to the specification.
6. This specification assumes that READY# goes active after the rising edge of phase 2, so that WR# goes
inactive as a result of READY# falling.
7. This specification assumes that READY# goes active before the rising edge of phase 2, so that WR# goes
inactive as a result of phase 2 rising.
8. This specification applies if READY# is generated internally.
Datasheet
39
Intel386™ EX Embedded Microprocessor
Table 12. 3-Volt AC Characteristics (Sheet 4 of 5)
25 MHz
3.0 V to 3.6 V
Symbol
20 MHz
2.7 V to 3.6 V
Test Condition
Parameter
Min.
(ns)
t103
STXCLK, SRXCLK High Time
t104
STXCLK Low to SSIOTX
Delay
t105
SSIORX to SRXCLK High
Setup Time
t106
SSIORX from SRXCLK Hold
Time
Max.
(ns)
7CLK2/
2
Min.
(ns)
Max.
(ns)
7CLK2/
2
3CLK2
(2)
3CLK2
0
0
3CLK2
3CLK2
(2)
Timer Control Unit (TCU) Inputs
t107
TMRCLK n Frequency
t108
TMRCLK n Low
60
60
t109
TMRCLK n High
60
60
t110
TMRGATEn High Width
50
50
t111
TMRGATEn Low Width
50
50
t112
TMRGATEn to TMRCLK
Setup Time (external
TMRCLK only)
10
15
t112a
TMRGATEn to TMRCLK Hold
Time (external TMRCLK only)
19
19
8
8
(Unit is MHz)
Timer Control Unit (TCU) Outputs
t113
TMRGATEn Low to TMROUT
Valid
44
52
t114
TMRCLK n Low to TMROUT
Valid
48
52
NOTE:
1. Tested at maximum operating frequency and guaranteed by design characterization at lower operating
frequencies.
2. These are not tested. They are guaranteed by characterization.
3. Float condition occurs when maximum output current becomes less than ILO in magnitude. Float delay is not
fully tested.
4. These inputs may be asynchronous to CLK2. The setup and hold specifications are given to ensure
recognition within a specific CLK2 period.
5. These specifications are for information only and are not tested. They are intended to assist the designer in
selecting memory speeds. For each wait state in the design add two CLK2 cycles to the specification.
6. This specification assumes that READY# goes active after the rising edge of phase 2, so that WR# goes
inactive as a result of READY# falling.
7. This specification assumes that READY# goes active before the rising edge of phase 2, so that WR# goes
inactive as a result of phase 2 rising.
8. This specification applies if READY# is generated internally.
40
Datasheet
Intel386™ EX Embedded Microprocessor
Table 12. 3-Volt AC Characteristics (Sheet 5 of 5)
25 MHz
3.0 V to 3.6 V
Symbol
20 MHz
2.7 V to 3.6 V
Test Condition
Parameter
Min.
(ns)
Max.
(ns)
Min.
(ns)
Max.
(ns)
Interrupt Control Unit (ICU) Inputs
t115
D7:0 Setup Time
(INTA# Cycle 2)
9
11
t116
D7:0 Hold Time
(INTA# Cycle 2)
6
6
Interrupt Control Unit (ICU) Outputs
t117
CLK2 High to CAS2:0 Valid
36
46
DMA Unit Inputs
t118
t119
t120
t121
t122
t123
t124
t125
DREQ Setup Time
(Sync Mode)
DREQ Hold Time
(Sync Mode)
DREQ Setup Time
(Async Mode)
DREQ Hold Time
(Async Mode)
EOP# Setup Time
(Sync Mode)
EOP# Hold Time
(Sync Mode)
EOP# Setup Time
(Async Mode)
EOP# Hold Time
(Async Mode)
19
21
4
4
11
11
11
11
17
21
4
4
11
11
11
11
(2)
(2)
DMA Unit Outputs
t126
DACK# Output Valid Delay
4
31
4
33
t127
EOP# Active Delay
4
27
4
33
t128
EOP# Float Delay
4
27
4
33
(3)
10
(Unit is MHz)
JTAG Test-logic Unit
t129
TCK Frequency
10
NOTE:
1. Tested at maximum operating frequency and guaranteed by design characterization at lower operating
frequencies.
2. These are not tested. They are guaranteed by characterization.
3. Float condition occurs when maximum output current becomes less than ILO in magnitude. Float delay is not
fully tested.
4. These inputs may be asynchronous to CLK2. The setup and hold specifications are given to ensure
recognition within a specific CLK2 period.
5. These specifications are for information only and are not tested. They are intended to assist the designer in
selecting memory speeds. For each wait state in the design add two CLK2 cycles to the specification.
6. This specification assumes that READY# goes active after the rising edge of phase 2, so that WR# goes
inactive as a result of READY# falling.
7. This specification assumes that READY# goes active before the rising edge of phase 2, so that WR# goes
inactive as a result of phase 2 rising.
8. This specification applies if READY# is generated internally.
Datasheet
41
Intel386™ EX Embedded Microprocessor
Figure 10. AC Test Loads
CPU Output
CL
Figure 11. CLK2 Waveform
t1
t2a
t2b
CLK2
A
B
C
t5
t3b
t4
t3a
A = Vcc – 0.8 for Vcc = 4.5 – 5.5, Vcc – 0.6 for Vcc = 2.7 – 3.6
B = Vcc/2
C = 0.8V
42
Datasheet
Intel386™ EX Embedded Microprocessor
Figure 12. AC Timing Waveforms — Input Setup and Hold Timing
TX
PH2
PH1
TX
PH2
PH1
TX
CLK2
READY# (Input)
BS8#
DREQ
EOP# (Input)
t19a, t118, t120
t122, t124
t19
t119, t121
t123, t125
t20
t23
t24
t115
t21
t116
t22
t29
t30
HOLD
D15:0
(Input)
BUSY#
ERROR#
PEREQ
t15
t16
t27a
t27
t28a
t28
NA#
NMI
SMI#
A2736-01
Datasheet
43
Intel386™ EX Embedded Microprocessor
Figure 13. AC Timing Waveforms — Output Valid Delay Timing
TX
PH2
PH1
TX
PH2
PH1
TX
CLK2
t8, t8a
BHE#, BLE#
LOCK#, SMIACT#
W/R#, M/IO#, D/C#
ADS#,REFRESH#
LBA#, DACK#
EOP# (Output)
READY# (Output)
Min
Valid n
Valid n+1
t10, t31, t33
t126, t127
Min
Max
Valid n+1
Valid n
t10a, t6, t34
Min
A25:1, CS6:0#,UCS#,
RD# Inactive
Max
Max
Valid n
Valid n+1
t117, t10a, t12
D15:0, CAS2:0
RD#, WR# Active,
WR# Inactive
(early READY#)
Min
Max
Valid n
Valid n+1
HLDA
A2737-01
Figure 14. AC Timing Waveforms — Output Valid Delay Timing for
External Late READY#
T1
T1
T2
CLK2
ADS#
External
READY#
t10b
WR#
A4398-01
44
Datasheet
Intel386™ EX Embedded Microprocessor
Figure 15. AC Timing Waveforms — Output Float Delay and HLDA Valid Delay Timing
TI or T1
Th
PH1
PH2
PH2
PH2
PH1
CLK2
t8
t9
BHE#, BLE#
LOCK#
Min
Max
Min
Max
Min
Max
Min
Max
(High Z)
t32, t11
W/R#, M/IO#
D/C#, ADS#
REFRESH#
READY# (Output)
Min
t10
Max
(High Z)
t7
Min
t6
Max
A25:1
(High Z)
t13
Min
t12
Max
D15:0
Max
Min
(High Z)
t13 Also applies to data float when write
cycle is followed by read or idle.
t14
Min
Max
t14
Min
Max
HLDA
A2738-01
Figure 16. AC Timing Waveforms — RESET Setup and Hold Timing and Internal Phase
Initialization Sequence
Reset
PH2 or PH1
PH2 or PH1
PH2
PH1
CLK2
t26
RESET
t25
Datasheet
45
Intel386™ EX Embedded Microprocessor
Figure 17. AC Timing Waveforms — Relative Signal Timing
T1
Ti
T2
CLK2
PH2
A25:1, BLE#, BHE#
UCS#, CS6:0#
t42
t41a
WR#
t41
t42a
t46
t44
t45
t43
D15:0 (Out)
t51
t52
RD#
t51a
t48
t47
t50
t47a
t49
D15:0 (In)
A2705-01
Figure 18. AC Timing Waveforms — SSIO Timing
t100, t101
t102
t103
STXCLK
t104
SSIOTX
Valid TX Data
t100, t101
t102
t103
SRXCLK
t105
SSIORX
t106
Valid RX Data
A2712-01
Figure 19. AC Timing Waveforms — Timer/Counter Timing
t107
t109
t108
TMRCLK
t112
t112a
t111
t110
TMRGATE
t113
t114
TMROUT
46
Datasheet
Intel386™ EX Embedded Microprocessor
7.0
Bus Cycle Waveforms
Figures 20 through 30 present various bus cycles that are generated by the processor. What is
shown in the figure is the relationship of the various bus signals to CLK2. These figures along with
the information present in AC Specifications allow the user to determine critical timing analysis for
a given application.
Figure 20. Basic Internal and External Bus Cycles
Idle
Cycle 1
Cycle Nonpipelined
External
(Write)
[Late Ready]
State
Ti
T1
T2
Idle
Cycle 3
Nonpipelined Cycle
Internal
(Write)
[Early Ready]
Cycle 2
Nonpipelined
Internal
(Read)
T1
T2
T1
T2
Ti
Idle
Cycle 4
Nonpipelined Cycle
External
(Read)
T1
T2
Ti
CLK2
CLKOUT
A25:1, BHE#
BLE#, D/C#
M/IO#
Valid 1
Valid 4
Valid 3
Valid 2
REFRESH#
W/R#
WR#
RD#
ADS#
NA#
READY#
End Cycle 1
End Cycle 2
End Cycle 3
End Cycle 4
LBA#
BS8#
LOCK#
D15:0
Valid 1
Out 1
Valid 2
Valid 3
In
2
Out 3
Valid 4
In
4
A2486-03
Datasheet
47
Intel386™ EX Embedded Microprocessor
Figure 21. Nonpipelined Address Read Cycles
Idle
Ti
Cycle 1
Non-pipelined
External
(Read)
T1
T2
Cycle 2
Non-pipelined
External
(Read)
T1
T2
Idle
T2
Ti
CLK2
CLKOUT
BHE#, BLE#, A25:1
M/IO#, D/C#
Valid1
Valid2
REFRESH#
W/R#
WR#
RD#
ADS#
NA#
READY#
End Cycle
End Cycle
LBA#
BS8#
LOCK#
D15:0
Valid1
Valid2
In1
In2
A2487-03
48
Datasheet
Intel386™ EX Embedded Microprocessor
Figure 22. Pipelined Address Cycle
Cycle 1
Pipelined
(Write)
[Late Ready]
T1P
T2P
T2P
Cycle 2
Non-pipelined
(Read)
T1P
T2
Cycle 3
Pipelined
(Write)
[Late Ready]
T1P
T2i
T2P
T2P
Cycle 4
Pipelined
(Read)
T1P
T2
CLK2
CLKOUT
BHE#, BLE#, A25:1,
M/IO#, D/C#
Valid1
Valid2
Valid3
Valid4
ADS# is asserted as
soon as the CPU has
another bus cycle to
perform, which is not
always immediately
after NA# is asserted.
W/R#
WR#
RD#
ADS#
Note ADS# is
asserted in
every T2P state.
As long as the CPU enters the T2P
state during Cycle 3, address
pipelining is maintained in Cycle 4.
NA#
Asserting NA# more
than once during
any cycle has no
additional effects
NA# could have been asserted in T1P
if desired. Assertion now is the latest
time possible to allow the CPU to enter
T2P state to maintain pipelining in cycle 3.
READY#
LBA#
BS8#
Valid 1
LOCK#
D15:0
Out
Out 1
Valid 2
Valid 3
In
2
Valid 4
Out 3
A2477-03
Datasheet
49
Intel386™ EX Embedded Microprocessor
Figure 23. 16-bit Cycles to 8-bit Devices (using BS8#)
State
Low Byte
Write
High Byte
Write
[Late Ready]
[Late Ready]
T1
T2
T1
T2
Low Byte
Read
High Byte
Read
T1
T1
T2
T2
Idle
Cycles
Ti
Ti
CLK2
CLKOUT
A25:1
M/IO#
D/C#
Valid 2
Valid 1
BLE#
BHE#
W/R#
WR#
RD#
ADS#
NA#
Must be high
READY#
BS8#
LOCK#
D15:8
D7:0
Valid 1
Valid 2
Data Out High
Data Out
Low
Data Out
High
Data
In
Low
Data
In
High
A3375-01
50
Datasheet
Intel386™ EX Embedded Microprocessor
Figure 24. Basic External Bus Cycles
Cycle 1
Nonpipelined
External
(Write)
[Late Ready]
State
T1
T2
Cycle 2
Nonpipelined
External
(Read)
T1
Cycle 3
Idle
Cycle Nonpipelined
External
(Write)
[Late Ready]
T2
Ti
T1
T2
Cycle 4
Nonpipelined
External
(Read)
T1
T2
CLK2
CLKOUT
A25:1, BHE#
BLE#, D/C#
M/IO#
Valid 1
Valid 2
Valid 3
Valid 4
Valid 1
Valid 2
Valid 3
Valid 4
REFRESH#
W/R#
WR#
RD#
ADS#
NA#
READY#
LBA#
BS8#
LOCK#
D15:0
Out 1
In 2
Out 3
In 4
A2305-02
Datasheet
51
Intel386™ EX Embedded Microprocessor
Figure 25. Nonpipelined Address Write Cycles
Idle
Ti
Cycle 1
Nonpipelined
External
(Write)
[Late Ready]
T1
T2
Cycle 2
Nonpipelined
External
(Write)
[Early Ready]
T1
T2
T2
Valid1
Valid2
Idle
Ti
CLK2
CLKOUT
BHE#, BLE#, A25:1
M/IO#, D/C#
REFRESH#
W/R#
WR#
RD#
ADS#
NA#
READY#
End Cycle 1
End Cycle 2
LBA#
BS8#
LOCK#
D15:0
Valid 1
Out 1
Valid 2
Out 2
A2488-02
52
Datasheet
Intel386™ EX Embedded Microprocessor
Figure 26. Halt Cycle
Cycle 1
Nonpipelined
(Write)
[Late Ready]
T1
T2
Idle
Cycle 2
Nonpipelined
(Halt)
T1
T2
Ti
Ti
Ti
Ti
CLK2
CLKOUT
BHE#, A1, M/IO#, W/R#
Valid 1
CPU remains halted until INTR, SMI#,
NMI, or RESET is asserted.
A25:2, BLE#, D/C#
Valid 1
CPU responds to HOLD input
while in the HALT state.
WR#
RD#
ADS#
NA#
READY#
†
LBA#
LOCK#
D15:0
Valid 1
Out
Valid 2
Undefined
Float
† HALT cycle must be acknowledged by READY# asserted. This READY# could be
generated internally or externally.
A2492-02
Datasheet
53
Intel386™ EX Embedded Microprocessor
Figure 27. Basic Refresh Cycle
Idle
Ti
Cycle 1
Nonpipelined
External
(Read)
T1
Idle
Idle
Cycle 2
Cycle 3
Nonpipelined
External
(Write)
[Late Ready]
Refresh
T2
Ti
T1
T2
T2
Ti
Ti
T1
T2
CLK2
CLKOUT
UCS#, CS6:0#,
BHE#, BLE#
M/IO#, D/C#
Valid 1
A25:1
Valid 1
Valid 3
Valid 2
Valid 3
REFRESH#
W/R#
WR#
RD#
ADS#
NA#
READY#
LBA#
LOCK#
D15:0
Valid 1
Valid 2
In
Float
Out
HOLD
HLDA
A2491-02
54
Datasheet
Intel386™ EX Embedded Microprocessor
Figure 28. Refresh Cycle During HOLD/HLDA
Idle
Ti
HOLD
Acknowledge
Th
Th
Th
Idle
Ti
Idle
Cycle 1
Refresh
T1
T2
Ti
HOLD
Acknowledge
Ti
Th
Th
CLK2
CLKOUT
BHE#, BLE#
M/IO#, D/C#
Floating
Floating
REFRESH#
A25:1
W/R#
Floating
Valid 1
Floating
Floating
Floating
Floating
Floating
Floating
Floating
Floating
Floating
WR#
RD#
ADS#
NA#
READY#
LBA#
LOCK#
Floating
D15:0
HOLD
HLDA
Due to refresh pending.
A2493-02
Datasheet
55
Intel386™ EX Embedded Microprocessor
Figure 29. LOCK# Signal During Address Pipelining
Unlocked
Bus Cycle
Locked
Bus Cycle
Locked
Bus Cycle
Unlocked
Bus Cycle
CLKOUT
Address Asserted
BLE#, BHE#, A25:1
LOCK Deasserted
LOCK#
READY#
A2489-02
Figure 30. Interrupt Acknowledge Cycles
Previous Interrupt
Cycle Acknowledge
Cycle 1
(Internal)
T2
T1
T2
Idle
(Four bus states)
Ti
Ti
Ti
Ti
Interrupt
Acknowledge
Cycle 2
(Internal)
T1
T2
Idle
Ti
Ti
CLK2
CLKOUT
BHE#
BLE#, A25:19,
CAS2:0,A15:3, A1
M/IO#, D/C#, W/R#
A2
WR#
RD#
ADS#
READY#
LBA#
LOCK#
A2490-03
56
Datasheet