1.0 System Overview

1.1 NS486SXL SYSTEM OVERVIEW

The NS486SXL is a highly integrated embedded system

controller. It includes an Intel486-class 32-bit processor, all

resources required for the System Service Elements of a

Real-Time Executive, and a selection of key I/O peripherals.

This “system-on-a-chip” is ideal for implementing a wide va-

riety of embedded applications.

The 32-bit processor core executes all of the Intel486 in-

structions with a similar number of clocks per instruction. An

on-board 1 Kbyte instruction cache provides for efficient ex-

ecution from ROM. Intel486 debug features are supported.

The processor has been optimized for operating system ker-

nels such as VRTX, VxWorks, pSOS+ and QNX. These en-

vironments only need the ’486 protected mode operation (no

real mode or virtual 8086 support), flat or linear memory ad-

dressing (no virtual memory paging), and floating point ex-

ecution in software only (no co-processor interface).

In fact, the NS486SXL includes all of the System Service El-

ements required by a typical kernel, including an efficient

DRAM controller that supports pagemode DRAMs for data

cache-like performance; three timer channels (including one

configured as a protected WATCHDOG Timer); two pro-

grammable 8259 interrupt controllers provide 15 on-chip in-

terrupt sources; an industry standard real time clock and cal-

endar

(RTC)

with

battery

backup;

and

support

for

comprehensive power management schemes.

In addition, the NS486SXL also incorporates the key I/O pe-

ripherals required for implementing a wide variety of embed-

ded applications: an industry standard high-performance

NS16550-compatible UART with HP-SIR and IrDA v1.0 in-

frared option, an 8254 timer, and a general purpose 2- or

3-wire synchronous serial interface for easy interface to low-

cost EEPROMs and other serial peripherals. System expan-

sion is supported with nine programmable Chip Select (CS)

signals and a generic ISA-type bus interface for external de-

vices and memory.

DS100121-2

***Indicates low-true signals

FIGURE 1. NS486SXL Internal Resource to Pins Map

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