NXP Semiconductors OM11077

Overview

LPC2478 from NXP Semiconductors is a 32-bit ARM7TDMI-S microcontroller operating at up to 72 MHz, featuring 512 kB flash, 98 kB SRAM (including 16 kB Ethernet RAM and 2 kB RTC-powered SRAM), integrated LCD controller supporting up to 1024×768 TFT/STN displays, dual CAN channels, USB 2.0 full-speed device/host/OTG with on-chip PHY, and 10/100 Ethernet MAC with MII/RMII - deployed in industrial control and medical systems requiring real-time I/O, graphics, and multi-protocol connectivity.

For engineers reviewing the LPC2478 datasheet, LPC2478 pinout, LPC2478 application, or LPC2478 equivalent, key selection considerations include its dual AHB bus architecture enabling concurrent Ethernet DMA, USB DMA, and flash execution; 160 GPIO pins with VIC-interrupt capability on 64 lines; and support for external SDRAM via EMC - critical for embedded HMI and networked edge devices.

Technical Context

The LPC2478 implements a dual Advanced High-performance Bus (AHB) system: one AHB dedicated to Ethernet DMA and USB DMA, the other to CPU and flash access - eliminating bus contention during high-throughput peripheral operation. Its ARM7TDMI-S core executes both 32-bit ARM and 16-bit Thumb instructions, with a 128-bit wide flash interface and accelerator enabling full 72 MHz performance from on-chip flash memory.

Peripherals are distributed across independent clock domains with individual dividers, enabling fine-grained power control; two power domains (core and I/O) and four reduced-power modes (idle, sleep, power-down, deep power-down) allow optimized energy use. The Vector Interrupt Controller (VIC) supports up to 32 vectored interrupts, with 64 GPIO pins directly mapped to edge-triggered interrupt inputs.

Key Specifications

Pinout & Package

Available in LQFP208 (SOT459-1) and TFBGA208 (SOT950-1) packages. Both variants feature identical pin functionality and electrical characteristics; LQFP208 offers through-hole reworkability while TFBGA208 enables compact PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microcontroller applications.

Compared with LPC2388 and STR912FAW44, the LPC2478 uniquely combines Ethernet MAC, USB OTG, LCD controller, and dual CAN in a single ARM7 package - making it optimal for cost-sensitive, space-constrained industrial HMIs requiring native wired connectivity and graphics.

Availability

LPC2478 is available at Aetrix Electronics and suitable for industrial control, medical systems, Point-of-Sale (POS) equipment, and portable electronics requiring stable component supply, long-term lifecycle assurance, and full traceability.

Supply support for LPC2478 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

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT markets.

The LPC2478 belongs to NXP's LPC2000 ARM7 microcontroller family, designed specifically for embedded applications demanding rich peripheral integration, real-time responsiveness, and low-power operation in resource-constrained environments.

FAQ

What is the maximum operating frequency of the LPC2478 microcontroller?

The LPC2478 microcontroller operates at a maximum system clock frequency of 72 MHz. This is achieved using the on-chip PLL, which can be driven by the main oscillator (1–25 MHz crystal), internal 4 MHz RC oscillator, or RTC oscillator. The 128-bit wide flash interface and accelerator ensure that the ARM7TDMI-S core sustains full 72 MHz performance when executing code directly from on-chip flash memory - a capability exclusive to the LPC2000 family.

Does the LPC2478 support external SDRAM, and what interface is used?

Yes, the LPC2478 supports external SDRAM via its External Memory Controller (EMC). The EMC provides dedicated control signals including RAS, CAS, CKE, DQM, and address/data buses, with programmable timing parameters for single-data-rate (SDR) SDRAM. It supports up to 32 MB of SDRAM, enabling large frame buffers for TFT displays or runtime heap expansion - critical for GUI-rich applications where on-chip 98 kB SRAM is insufficient.

How many CAN interfaces does the LPC2478 integrate, and are they fully compliant?

The LPC2478 integrates two Controller Area Network (CAN) 2.0B-compliant controllers. Each channel supports both standard (11-bit) and extended (29-bit) identifier formats, bit rates up to 1 Mbps, and full message object management. CAN1 and CAN2 operate independently with dedicated receive/transmit pins (e.g., P0[0]/RD1/TXD3 for CAN1), allowing simultaneous operation on separate buses - commonly used in industrial automation for machine coordination and diagnostics.

What LCD display resolutions and types does the LPC2478's built-in controller support?

The LPC2478's LCD controller supports both Super-Twisted Nematic (STN) and Thin-Film Transistor (TFT) displays, with programmable resolution up to 1024×768 pixels and color depth up to 24-bit true color (RGB888). It includes dedicated DMA for pixel data transfer, reducing CPU load, and supports multiple display modes including passive matrix STN and active matrix TFT with RGB or YUV interfaces - enabling high-fidelity HMI in medical monitors and industrial panels.

Can the LPC2478 operate in low-power modes, and how is wake-up managed?

Yes, the LPC2478 supports four reduced-power modes: idle, sleep, power-down, and deep power-down. Wake-up from power-down mode is possible via multiple sources including external interrupts (EINT0–EINT3), RTC alarm, USB activity, Ethernet wake-on-LAN, CAN bus activity, and GPIO pins on Port 0/Port 2 configured as edge-sensitive interrupts. The 2 kB RTC-powered SRAM retains data during deep power-down, enabling state preservation across extended battery-off periods in portable devices.