NS486SXL-25 National Semiconductor, NS486SXL-25 Datasheet - Page 3

• Manufacturer Part Number: NS486SXL-25
• Description: IC NS486SXL 132PQFP
• Manufacturer: National Semiconductor

Specifications of NS486SXL-25

• Processor Type: 486SX
• Speed: 25MHz
• Voltage: 3.3V, 5V
• Mounting Type: Surface Mount
• Package / Case: 132-MQFP, 132-PQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Features: -
• Other names: *NS486SXL-25

1 0 System Overview
1 1 NS486SXF SYSTEM OVERVIEW
The NS486SXF 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 generous set of peripherals
This ‘‘system-on-a-chip’’ is ideal for implementing a wide
variety of embedded applications These include (but are
not limited to) fax machines multifunction peripherals (fax
scanners printers) mobile companions (both organizer and
communicator) television set-top boxes and telephones
(mobile and desktop)
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
kernels such as VRTX VxWorks pSOS
environments only need the ’486 protected mode operation
(no real mode or virtual 8086 support) flat or linear memory
addressing (no virtual memory paging) and floating point
execution in software only (no co-processor interface)
In fact the NS486SXF includes all of the System Service
Elements required by a typical kernel including an efficient
DRAM controller that supports page-mode DRAMs for data
FIGURE 1-1 NS486SXF Internal Resource to Pins Map
a
and QNX These
3
cache-like performance a six channel DMA controller with
two channels supporting data transfers from on-chip periph-
erals (the IEEE 1284 ECP or Extended Capabilities Port
and the LCD controller) and four channels supporting exter-
nal devices such as scanners and print engines three timer
channels (including one configured as a protected WATCH-
DOG Timer) two programmable 8259 interrupt controllers
for 15 on-chip interrupt sources an industry standard real
time clock and calendar (RTC) with battery backup and
support for comprehensive power management schemes
In addition the NS486SXF also incorporates the key I O
peripherals required for implementing a wide variety of em-
bedded applications an IEEE 1284 Bidirectional Parallel
Port that includes both Host and Slave modes an Intel
82365-compatible PCMCIA controller for one card slot an
industry standard high-performance NS16550-compatible
UART with HP-SIR and IrDA v1 0 infrared option an LCD
panel interface with DMA supported refresh for many of the
standard resolutions 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
expansion is supported with nine programmable Chip Select
(CS) signals and a generic ISA-type bus interface for exter-
nal devices and memory
TL EE 12514– 2