Intel Embedded Intel486 Hardware Reference Manual page 29

The Intel486™ processor family enables a range of low-cost, high-performance embedded sys-
tem designs capable of running the entire installed base of DOS*, Windows*, OS/2*, and UNIX*
applications written for the Intel architecture. This family includes the following processors:
• The IntelDX4™ processor is the fastest Intel486 processor (up to 50% faster than an
IntelDX2™ processor). The IntelDX4 processor integrates a 16-Kbyte unified cache and
floating-point hardware on-chip for improved performance.
The IntelDX4 processor is also available with a write-back on-chip cache for improved
entry-level performance.
• The IntelDX2™ processor integrates an 8-Kbyte unified cache and floating-point
hardware on-chip.
The IntelDX4 and IntelDX2 processors use Intel's speed-multiplying technology, allowing
the processor core to operate at frequencies higher than the external memory bus.
• The Intel486 SX processor offers the features of the IntelDX2 processor without floating-
point hardware and clock multiplying.
• The Ultra-Low Power Ultra-Low Power Intel486 SX and Ultra-Low Power
Intel486 GX processors provide additional power-saving features for use in battery-
operated and hand-held embedded designs. The Ultra-Low Power Intel486 SX processor,
like the other Intel486 processors, supports dynamic data bus sizing for 8-, 16-, or 32-bit
bus sizes, whereas the Ultra-Low Power Intel486 GX processor has a 16-bit external data
bus.
The entire Intel486 processor family incorporates energy efficient "SL Technology" for mobile
and fixed embedded computing. SL Technology enables system designs that exceed the Environ-
mental Protection Agency's (EPA) Energy Star program guidelines without compromising per-
formance. It also increases system design flexibility and improves battery life in all Intel486
processor-based hand-held applications. SL Technology allows system designers to differentiate
their power management schemes with a variety of energy efficient, battery life enhancing fea-
tures.
Intel486 processors provide power management features that are transparent to application and
operating system software. Stop Clock, Auto HALT Power Down, and Auto Idle Power Down
allow software-transparent control over processor power management.
Equally important is the capability of the processor to manage system power consumption.
Intel486 processor System Management Mode (SMM) incorporates a non-maskable System
Management Interrupt (SMI#), a corresponding Resume (RSM) instruction and a new memory
space for system management code. Although transparent to any application or operating system,
Intel's SMM ensures seamless power control of the processor core, system logic, main memory,
and one or more peripheral devices.
CHAPTER 2
INTRODUCTION
2-1