Intel 386 User Manual

Intel386™ EX EMBEDDED MICROPROCESSOR USER’S MANUAL
12-2
Figure 12-1. DMA Unit Block Diagram
A2531-02
DREQ0
DMAACK0#
DREQ1
DMAACK1#
DMAINT
DMA
Bus Arbiter
HOLD
HLDA
RBFDMA1 (SIO1 )
TXEDMA0 (SIO0)
SSRBF (SSIO)
DRQ0
(DCD1#)†
To SIO1
DRQ1
(RXD1)
To SIO1
DACK0#
(CS5#)
DMACFG.3
From CSU
DACK1#
(TXD1)
DMACFG.7
From SIO1
DMACFG.6:4
3
DMACFG.2:0
PINCFG.4
PINCFG.2
EOP#
(CTS1#)
From SIO1
PINCFG.3
HOLD
(P1.6)
To/From I/O Port 1
P1CFG.6
HLDA
(P1.7)
To/From I/O Port 1
P1CFG.7
3
† Alternate pin signals are in parentheses.
End of Process
OUT2 (TCU)
RBFDMA0 (SIO0)
TXEDMA1 (SIO1)
SSTBE (SSIO)
0
1
2
3
4
5
6
7
RBFDMA0 (SIO0)
TXEDMA1 (SIO1)
SSTBE (SSIO)
OUT1 (TCU)
RBFDMA1 (SIO1)
TXEDMA0 (SIO0)
SSRBF (SSIO)
0
1
2
3
4
5
6
7
1
0
1
0
1
0
0
1
1
0
To ICU

Intel 386 Specifications

General

Architecture	x86
Clock Speed	12 MHz to 40 MHz
Transistor Count	275, 000
Data Bus Width	32-bit
Address Bus Width	32-bit
Instruction Set	x86
Introduced	1985
Maximum Memory	4 GB
Operating Modes	Real mode, Protected mode, Virtual 8086 mode
MMU	Yes
Voltage	5V
Model	Intel 386
Package	PGA
Process	1.5 μm to 1 μm