This document contains information on a product under development at Advanced Micro Devices. The information is
intended to help you evaluate this product. AMD reserves the right to change or discontinue work on this proposed
product without notice.
Advanced
Micro
Devices
DISTINCTIVE CHARACTERISTICS
a73 High-Performance Design
— Industry-standard write-back cache support
— Frequent instructions execute in one clock
— 105.6-million bytes/second burst bus at 33 MHz
— Flexible write-through and write-back address
control
— Advanced 0.35-µ CMOS-process technology
— Dynamic bus sizing for 8-, 16-, and 32-bit buses
— Supports “soft reset” capability
a73 High On-Chip Integration
— 16-Kbyte unified code and data cache
— Floating-point unit
— Paged, virtual memory management
a73 Enhanced System and Power Management
— Stop clock control for reduced power
consumption
— Industry-standard two-pin System Management
Interrupt (SMI) for power management indepen-
dent of processor operating mode and operating
system
— Static design with Auto Halt power-down support
— Wide range of chipsets supporting SMM avail-
able to allow product differentiation
a73 Complete 32-Bit Architecture
— Address and data buses
— All registers
— 8-, 16-, and 32-bit data types
a73 Standard Features
— 3-V core with 5-V tolerant I/O
— Available in a 133-MHz version
— Binary compatible with all Am486
®
DX,
Am486DX2, and Am486DX4 microprocessors
— Wide range of chipsets and support available
through the AMD FusionPC
SM
Program
a73 168-pin PGA package or 208-pin SQFP package
a73 IEEE 1149.1 JTAG Boundary-Scan Compatibility
a73 Supports Environmental Protection Agency's
Energy Star program
— 3-V operation reduces power consumption up to
40%
— Energy management capability provides excel-
lent base for energy-efficient design
— Works with a variety of energy-efficient, power-
managed devices
GENERAL DESCRIPTION
The Am5
X
86™ microprocessor is an addition to the AMD
microprocessor product family. The new processor en-
hances system performance by raising the microproces-
sor operating frequency to the highest levels allowed by
current manufacturing technology, while maintaining
complete compatibility with the standard Am486 proces-
sor architecture and Microsoft
®
Windows
®
. The CPUs
incorporate write-back cache, flexible clock control, and
enhanced SMM. Table 1 shows available processors
in the Am5
X
86 microprocessor family.
The Am5
X
86 microprocessor family allows write-back
configuration through software and cacheable access
control. On-chip cache lines are configurable as either
write-through or write-back. The CPU clock control fea-
ture permits the CPU clock to be stopped under con-
trolled conditions, allowing reduced power consumption
during system inactivity. The SMM function is implement-
ed with an industry standard two-pin interface.
Table 1. Clocking Options
Operating
Frequency
Input Clock Available Package
133 MHz 33 MHz 168-pin PGA
133 MHz 33 MHz 208-pin SQFP
PRELIMINARY
Am5
X
86™
Microprocessor Family
Publication # 19751 Rev: C Amendment/0
Issue Date: March 1996