F I N A L
BLOCK DIAGRAM
Segmentation Unit
Paging Unit
Adder
Bus Control
HOLD, INTR,
NMI, ERROR,
BUSY, RESET,
HLDA, FLT,
3-Input
Adder
Request
Prioritizer
Effective Address Bus
32
32
25
32
SMI*, IIBEN*
Descriptor
Registers
Page
Cache
Effective Address Bus
Control
and
Limit and
Attribute
PLA
Attribute
BHE, BLE,
A23-A1
Protection
Test Unit
Address
Driver
PLA
M/IO, D/C,
W/R, LOCK,
ADS, NA,
READY,
SMIADS*,
SMIRDY*
Pipeline/
Bus Size
Control
Internal Control Bus
MUX/
Trans-
ceivers
Barrel
Shifter,
Adder
D15-D0
Decode
and
Sequencing
Prefetcher/
Limit
Checker
Instruction
Decoder
32
Status
Flags
Multiply/
Divide
Code
Stream
16-Byte
Code
Queue
3-Decoded
Instruction
Queue
Control
ROM
Register
File
ALU
Control
32 Bit
Control
Instruction
Predecode
Instruction
Prefetch
Dedicated ALU Bus
ALU
32
* – On Am386SXLV only
FUNCTIONAL DESCRIPTION
plifies the design of power-conscious portable applica-
tions in the following ways.
True Static Operation
(Am386SXL/SXLV Only)
■ Eliminates the need for software in BIOS to save
The Am386SXL/SXLV microprocessor incorporates a
true static design. Unlike dynamic circuit design, the
Am386SXL/SXLV device eliminates the minimum op-
erating frequency restriction. It may be clocked from its
maximum speed all the way down to 0 MHz (DC). Sys-
tem designers can use this feature to design portable
applications with long battery life.
and restore the contents of registers.
■ Allows simpler circuitry to control stopping of the
clock since the system does not need to know
the state of the processor.
Lower Operating Icc
(Am386SXL/SXLV Only)
Standby Mode (Am386SXL/SXLV Only)
True static design also allows lower operating Icc when
operating at any speed.
The true static design of the Am386SXL/SXLV micro-
processor allows for a Standby Mode. At any operating
speed, the microprocessor will retain its state (i.e., the
contents of all its registers). By shutting off the clock
completely, the device enters Standby Mode. Since
power consumption is proportional to clock frequency,
operating power consumption is reduced as the fre-
quency is lowered. In Standby Mode, typical current
draw is reduced to less than 20 microamps at DC. Not
only does this feature save battery life, but it also sim-
Performance on Demand
(Am386SXL/SXLV Only)
The Am386SXL/SXLV microprocessor retains its state
at any speed from 0 MHz (DC) to its maximum operat-
ing speed. With this feature, system designers may
vary the operating speed of the system to extend the
battery life in portable systems.
Am386SX/SXL/SXLV Microprocessors Data Sheet
3
AMD [ AMD ]
