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Texas Instruments NS486SXF-25/NOPB
- Part No.:
- NS486SXF-25/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Microprocessors
- Package:
- 160-BFQFP
- Datasheet:
-
NS486SXF-25/NOPB.pdf
- Description:
- IC MPU INTEL486 SX 25MHZ 160QFP
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
NS486SXF-25/NOPB from National Semiconductor is a 32-bit embedded system controller integrating an Intel486-class protected-mode CPU core, on-chip DRAM controller (supporting up to 16 MB total), six-channel DMA, IEEE 1284 ECP parallel port, PCMCIA 2.0 interface, UART with IrDA v1.0, LCD controller (480×320), and reconfigurable I/O - all in a single 160-pin PQFP package operating at 25 MHz on 5 V. It targets fax machines, multifunction peripherals, set-top boxes, and mobile communicators.
For engineers reviewing the NS486SXF-25/NOPB datasheet, NS486SXF-25/NOPB pinout, NS486SXF-25/NOPB application, or NS486SXF-25/NOPB equivalent, key selection considerations include its 25 MHz 5V operation, glueless ISA-compatible bus, protected-mode-only 486 instruction set, integrated real-time clock/calendar, and programmable power management for battery-operated embedded systems.
Technical Context
The NS486SXF-25/NOPB implements a RISC-optimized 32-bit processor core executing Intel486 protected-mode instructions with a 1 KB instruction cache and three-stage pipeline - no real mode, virtual memory, or FPU support. It boots directly into protected mode and uses a 50 MHz crystal divided by two for its 25 MHz CPU clock.
Its system service elements include a dual-bank DRAM controller (page-mode, up to 8 MB per bank), six-channel DMA (four external, two internal to ECP/LCD), dual cascaded 8259-compatible interrupt controllers (15 IRQs), 1 kHz protected WATCHDOG timer (CH2), and DS1287-compatible RTC with 50-byte CMOS RAM and alarm functions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| CPU Core | Intel486-class, protected-mode only; boots directly into protected mode - eliminates real-mode initialization overhead and reduces silicon area. |
| Operating Frequency | 25 MHz at 5 V ±5%; derived from 50 MHz crystal via on-chip divide-by-2 - simplifies clock sourcing and reduces external component count. |
| DRAM Support | Two banks, up to 8 MB each; page-mode read/write; programmable CAS-before-RAS refresh - enables fast contiguous data access without external cache. |
| DMA Channels | Six total: four external (25 MB/s max @ 25 MHz), two internal (to ECP port and LCD controller) - offloads high-bandwidth transfers from CPU for real-time display and printing. |
| Parallel Interface | IEEE 1284 ECP mode with Host/Slave capability - supports bidirectional high-speed peripheral control (e.g., printers, scanners) without external logic. |
| LCD Controller | Supports 480×320 monochrome grayscale displays with DRAM-based frame buffer and 60–90 Hz refresh - enables embedded GUIs with minimal external video components. |
| Power Management | CPU clock division (÷4, ÷8, ÷16, ÷32, ÷64), per-peripheral clock gating, and idle-mode CPU clock disable - achieves granular power control for portable and low-power systems. |
Pinout & Package
The NS486SXF-25/NOPB is housed in a 160-pin Plastic Quad Flat Package (PQFP) compliant with JEDEC MS-026, measuring 28 mm × 28 mm with 0.65 mm lead pitch. Thermal and mechanical data align with National Semiconductor's standard PQFP specifications for embedded industrial use.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SA[25:0] | System Address Bus | 26-bit multiplexed address output; carries latched CPU address or cascaded interrupt vectors; SA[0] sampled at reset to select ICE mode. |
| SD[15:0] | System Data Bus | 16-bit bidirectional data path; upper byte (SD[15:8]) unused during 8-bit transfers - supports mixed 8/16-bit peripheral interfacing. |
| SBHE | Byte High Enable | Active-low signal indicating high-byte transfer on SD[15:8]; sampled at power-on to detect boot ROM width - enables automatic 8/16-bit memory configuration. |
| IOR / IOW | I/O Read/Write Control | Active-low strobes for I/O-mapped transactions; compatible with ISA timing - allows direct connection to legacy ISA peripherals without glue logic. |
| MEMR / MEMW | Memory Read/Write Control | Active-low strobes for memory-mapped accesses; synchronized with SA/SD - supports external SRAM, Flash, and DRAM with wait-state insertion via RDY. |
| RDY | Wait-State Input | Open-collector or tri-state input to extend bus cycles; driven low by slow peripherals - enables flexible timing adaptation without CPU modification. |
Key Features
| Feature | Design Value |
|---|---|
| Reconfigurable I/O | Up to 29 pins dynamically reassigned as general-purpose bidirectional I/O when UART, ECP, LCD, or PCMCIA functions are disabled - maximizes pin utility across product variants. |
| PCMCIA Interface | Single-slot PCMCIA 2.0 support with ExCA 1.50 and XIP capability - enables hot-pluggable storage and modem expansion with minimal external circuitry. |
| IrDA v1.0 UART | NS16550-compatible serial port with 16-byte FIFO and HP-SIR infrared mode - delivers reliable wireless data exchange at up to 115.2 kbps without external transceivers. |
| WATCHDOG Timer | Protected 16-bit CH2 timer driven by 1 kHz RTC clock; generates reset/interrupt on timeout - ensures deterministic recovery from firmware hangs in unattended systems. |
| MICROWIRE/Access.bus | Configurable 2-wire (Access.bus) or 3-wire (MICROWIRE/SPI-phase) serial interface - simplifies connection to EEPROMs, A/D converters, and clock chips using industry-standard protocols. |
Applications
| Fax Machine Control | Multifunction Peripheral (MFP) |
|---|---|
Use Scenario: Integrated fax engine managing document scanning, compression, modem transmission, and thermal printing. IC Role / Device Role / Timing Role: Central controller executing real-time OS (VRTX/pSOSa), coordinating DRAM-buffered image processing, PCMCIA-based firmware updates, and IrDA-linked status reporting. Use Value: Single-chip integration eliminates discrete DMA, UART, and timer ICs; ECP port drives printer engine directly; 25 MHz performance sustains G3 fax throughput. | Use Scenario: Shared platform for scanner, copier, and printer functions with interchangeable firmware and modular hardware. IC Role / Device Role / Timing Role: System-on-chip host managing concurrent LCD UI, USB/ECP peripheral arbitration, DRAM-based scan buffer, and RTC-scheduled tasks. Use Value: Reconfigurable I/O adapts pinout to module presence; LCD controller drives 320×240 panel natively; nine chip selects enable flexible peripheral expansion. |
| Set-Top Box (STB) | Mobile Communicator |
Use Scenario: Digital TV receiver decoding MPEG-2 streams, rendering OSD menus, and handling IR remote input. IC Role / Device Role / Timing Role: Protected-mode kernel host running QNX Neutrino; DRAM controller buffers video frames; UART handles IR demodulation and debug console. Use Value: 1 KB instruction cache improves code fetch efficiency from Flash; power management modes reduce standby current; RTC maintains EPG time. | Use Scenario: Handheld organizer with PDA functionality, SMS messaging, and infrared file exchange. IC Role / Device Role / Timing Role: Real-time executive host (VxWorks) managing LCD refresh, IrDA v1.0 comms, battery-backed RTC alarms, and PCMCIA modem card. Use Value: Integrated IrDA PHY eliminates external transceiver; 29 reconfigurable I/O pins support custom keypad and sensor interfaces; low-power idle modes extend battery life. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar embedded controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AMD ÉLAN SC400-25 | 25 MHz x86-compatible core with integrated PCI, USB 1.1, and enhanced power management; larger die, different pinout. | Targets higher-integration designs requiring USB connectivity and PCI expansion - not drop-in compatible. | Select for new designs needing USB/PCI; avoid for NS486SXF-25/NOPB footprint or software migration. |
| Intel 386EX C33 | 33 MHz 386SX core with integrated timers, UART, and watchdog; no ECP port, LCD controller, or PCMCIA; 132-pin LQFP. | Suitable for simpler control applications without graphics or high-speed parallel I/O - lower gate count and cost. | Choose when LCD/ECP/PCMCIA are unnecessary and legacy 386 toolchains are preferred. |
Compared with AMD ÉLAN SC400-25 and Intel 386EX C33, the NS486SXF-25/NOPB uniquely combines 486-class performance with integrated ECP, LCD, and PCMCIA in a 160-pin PQFP - making it optimal for cost-sensitive, graphics-capable embedded systems where those peripherals are essential.
Availability
NS486SXF-25/NOPB is available at Aetrix Electronics and suitable for fax machines, multifunction peripherals, set-top boxes, and mobile communicators requiring stable component supply across long-lifecycle embedded programs.
Supply support for NS486SXF-25/NOPB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
National Semiconductor was a U.S.-based semiconductor company specializing in analog, interface, and embedded controller solutions before its acquisition by Texas Instruments in 2011.
The NS486SXF product line was designed as a highly integrated, cost-optimized 486-class embedded controller targeting office automation and communication devices - emphasizing glueless ISA compatibility, power efficiency, and peripheral consolidation.
FAQ
What is the maximum DRAM capacity supported by the NS486SXF-25/NOPB?
The NS486SXF-25/NOPB supports up to 16 MB of DRAM total: two independently configurable banks, each up to 8 MB. Each bank uses a 16-bit data path and supports page-mode operations with programmable CAS latency and refresh timing. Parity support requires 18-bit-wide DRAMs when enabled.
Does the NS486SXF-25/NOPB support real-mode x86 execution?
No, the NS486SXF-25/NOPB operates exclusively in protected mode and does not support real-mode or virtual 8086 mode. Its processor core omits real-mode initialization logic, floating-point unit interface, and virtual memory paging - optimizations that reduce die size and power consumption for embedded RTOS environments like VxWorks and QNX Neutrino.
Can the NS486SXF-25/NOPB drive a color LCD display?
No, the NS486SXF-25/NOPB LCD controller is limited to monochrome supertwist displays with up to 4 gray levels (1- or 2-bit per pixel). It supports resolutions including 320×240, 320×200, and 480×320 but lacks hardware acceleration, RGB interface, or color palette registers required for color TFT or STN panels.
How many interrupt sources does the NS486SXF-25/NOPB provide?
The NS486SXF-25/NOPB provides 15 programmable interrupt sources via two cascaded 8259A-compatible interrupt controllers. Three IRQs are reserved for RTC tick, RTC alarm, and cascade channel; the remaining 12 are available for internal peripherals (UART, timers, ECP) or external devices connected to the ISA-like bus.
Is the NS486SXF-25/NOPB pin-compatible with the NS486TMSXF variant?
Yes, the NS486SXF-25/NOPB and NS486TMSXF share identical 160-pin PQFP packaging, pinout, and electrical characteristics. The TMSXF variant adds temperature monitoring circuitry but maintains full functional and mechanical compatibility - allowing direct substitution in thermally constrained industrial applications without PCB changes.
NS486SXF-25/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 160-BFQFP
- Series:
- -
- Packaging:
- Tray
- Product Status:
- Active
- Core Processor:
- Intel486 SX
- Number of Cores/Bus Width:
- 1 Core, 32-Bit
- Speed:
- 25MHz
- Co-Processors/DSP:
- -
- RAM Controllers:
- DRAM
- Graphics Acceleration:
- No
- Display & Interface Controllers:
- LCD
- Ethernet:
- -
- SATA:
- -
- USB:
- -
- Voltage - I/O:
- 3.3V, 5.0V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Security Features:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 160-QFP (28x28)
- Additional Interfaces:
- Access.bus, IrDA, Microwire, PCMCIA, UART
NS486SXF-25/NOPB FAQ
1.How can I place an order for NS486SXF-25/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for NS486SXF-25/NOPB on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for NS486SXF-25/NOPB reliable?
The price and inventory of NS486SXF-25/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for NS486SXF-25/NOPB is usually 5 days.
3.What payment methods are accepted for NS486SXF-25/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for NS486SXF-25/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for NS486SXF-25/NOPB?
NS486SXF-25/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your NS486SXF-25/NOPB order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for NS486SXF-25/NOPB?
For technical support, including NS486SXF-25/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your NS486SXF-25/NOPB requirements.
6.How does Aetrix verify that NS486SXF-25/NOPB is sourced from the original manufacturer or authorized distributors?
All NS486SXF-25/NOPB products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that NS486SXF-25/NOPB meets industry standards.
7.What is the process for return or replacement of NS486SXF-25/NOPB?
All NS486SXF-25/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with NS486SXF-25/NOPB, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The NS486SXF-25/NOPB part is unused and in its original packaging.
Return procedure for NS486SXF-25/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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