NXP microcontrollers with LCD - unique functions, low-cost integration

Liquid Crystal Displays (LCDs), especially those with color and touchscreen capabilities, make embedded systems much easier to use. As a result, they've become commonplace across the consumer, medical, industrial, recreational, communication, and automotive sectors. In recent years, the external LCD interface that has traditionally connected the LCD panel to the MCU has moved onto the MCU itself, providing engineers with integrated options that reduce cost, shrink the design, increase reliability, and shorten time-to-market.

NXP offers the industry's most advanced line of LCD-based MCUs. It began in 2007, when NXP acquired Sharp's BlueStreak product line. The acquisition added a family of LCD-based ARM7 and ARM9 MCUs to the portfolio, and established a team of NXP system and software engineers with extensive expertise in LCD connectivity. Since then, NXP has continued to grow its LCD-based MCU line.

Controlling an LCD panel requires high bandwidth and constant refreshes. The higher the display's resolution, the harder the controller has to work. NXP's LCD controller architecture is designed to lessen these impacts. The architecture delivers best-in-class performance while offloading the CPU and improving power efficiency.

NXP's LCD controller supports up to 24-bpp color space and up to 1024 x 768 pixels. It works with STN and TFT colors and uses a color palette that reduces bus utilization while supporting a large number of colors. It also includes its own DMA controller, for full operation independent of the CPU and other system functions. Support for a hardware cursor further reduces the amount of CPU time needed to operate the display, and a built-in FIFO acts as a buffer for display data, enabling flexible system timing.

NXP's ARM7 MCUs include an LCD controller and support USB and Ethernet connectivity. To improve the performance of these demanding operations, the ARM7 architecture uses a second AHB bus dedicated to Ethernet operations. This frees up the main bus to provide bandwidth for LCD refreshes.

Dual AHB Structure (LPC24xx)

In its ARM9 MCUs, NXP uses a multilayered bus matrix connecting the ARM CPU and other bus masters (e.g. LCD controller, Ethernet, USB) to peripherals and the external bus interface. The structure adds flexibility and optimizes performance by allowing peripherals that are on different layers of the matrix to be accessed simultaneously by different bus masters.

To make display refreshes more efficient, NXP's LCD controller integrates a larger-than-average cache and internal SRAM. The large cache size gives the LCD controller extra bandwidth by reducing the CPU's need to access external memory. The SRAM can be used as a frame buffer, to further reduce or even eliminate the need to access external memory for refreshes.

NXP's LCD-based MCUs integrate an A/D converter with support for a touchscreen controller, so it's easy and cost-effective to add touchscreen capabilities to a system.

Core	Product	LCD Controller (bpp)	Touchscreen Interface	USB	Ethernet 10/100
ARM7TDMI	LH75401	12-Bit	Yes	No	No
	LH75411	12-Bit	Yes	No	No
	LPC247x	24-Bit	Yes	Yes	Yes
ARM720T	LH79520	16-Bit	No	No	No
	LH79524	24-Bit	Yes	Yes	Yes
	LH79525	24-Bit	Yes	Yes	Yes
ARM922T	LH7A400	16-Bit	No	Yes	No
	LH7A404	16-Bit	Yes	Yes	No
ARM926EJ	LPC3230	24-Bit	Yes	Yes	No
	LPC3250	24-Bit	Yes	Yes	Yes

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LH75401 System-on-Chip with ARM7TDMI-S microcontroller, 32KB SRAM, LCD controller up to 12-bit or XGA, AHB, APB, external memory interface, CAN

LH75411 System-on-Chip with ARM7TDMI-S microcontroller, 32KB SRAM, LCD controller up to 12-bit or XGA, AHB, APB, external memory interface

LH79520 System-on-Chip with ARM720T microcontroller, 32KB SRAM, LCD controller up to true color or SVGA, MMU, AHB, APB, external memory interface

LH79524 System-on-Chip with ARM720T microcontroller, 16KB SRAM, LCD controller up to true color or XGA, touch screen controller, MMU, AHB, APB, 32-bit external memory interface, USB 1.1 full speed device, 10/100 ethernet, I2C, 10-bit ADC

LH79525 System-on-Chip with ARM720T microcontroller, 16KB SRAM, LCD controller up to true color or XGA, touch screen controller, MMU, AHB, APB, 16-bit external memory interface, USB 1.1 full speed device, 10/100 ethernet, I2C, 10-bit ADC

LPC2470 ROMless microcontroller with dual AHB bus architecture, external memory interface, LCD STN/TFT controller, USB 2.0 device/host/OTG, 10/100 ethernet, SD/MMC, I2S, real-time emulation

LPC2478 Microcontroller with dual AHB accelerator architecture, 512KB flash, external memory interface, LCD STN/TFT controller, USB 2.0 device/host/OTG, 10/100 ethernet, SD/MMC, I2S, real-time emulation

• Refine These with the ARM7 Core MCUs Parametric Filter

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LH7A400 System-on-Chip with ARM9TDMI microcontroller, 80KB SRAM, LCD controller up to 16-bit and XGA, MMU, AC97 audio, AHB, APB, external memory interface, USB 1.1 full speed device, PCMCIA, CF, MMC, Smart Card

LH7A404 System-on-Chip with ARM9TDMI microcontroller, 80KB SRAM, LCD controller up to 16-bit and XGA, touch screen controller, MMU, AC97 audio, AHB, APB, external memory interface, USB 1.1 full speed host/device, PCMCIA, CF, SD/MMC, Smart Card, 9x10-bit ADC, PS/2

LPC3230 ARM926-EJS microcontroller with 256KB SRAM, hardware vector floating-point coprocessor, USB On-The-Go host/device, SDRAM memory interface, LCD controller, SD interface

LPC3250 ARM926-EJS microcontroller with 256KB SRAM, hardware vector floating-point coprocessor, USB On-The-Go host/device, SDRAM memory interface, 10/100 ethernet, LCD controller, SD interface

• Refine These with the ARM9 Core MCUs Parametric Filter

• Graphical User Interface emWin (by SEGGER)
• Graphical User Interface μC/GUI (by Micrium)
• Graphical User Interface PEG+ (by Swell Software)
• I²C-Bus LCD Driver Evaluation Board Demo Program Source Code, V2.01 (Feb 2, 2009)
• I²C-Bus LCD Driver Evaluation Board Demo Program Source Code (Previous Version), V1.1 (Dec 11, 2008)
• LPC247x LCD Bus Load Calculator (May 23, 2007)
• LPC32x0 Rev 'A' LCD Bus Load Calculator (Jul 21, 2009)

• Refine These Support Documents Matches

• LCD Controller Design Examples Using the LPC247x

• AN10675 Interfacing 4-wire and 5-wire resistive touchscreens to the LPC2300, V2 (Nov 13, 2008)
• AN10815 SWIM: NXP's basic graphics library for LPC products (with software), V1 (May 1, 2009)
• AN10880 Using the LCD interface in the LPC313x/LPC314x/LPC315x devices, V1 (Oct 21, 2009)
• LH79520 Combining On-chip SRAM with External SDRAM to Construct a Low-latency LCD Frame Buffer (Sep 13, 2007)
• LH79520 LH79520 System-On-Chip LCD Interfacing Guide (Sep 13, 2007)
• LH7A40x Driving an STN Monochrome LCD with the LH7A400 or LH7A404 (Sep 13, 2007)
• LH7xxxx Using the NXP ADC with Resistive Touch Screens (Jul 24, 2008)

• Refine These Support Documents Matches

• TN08002 LPC32x0 Rev '-' LCD Bus Load Calculator, V2.0 (Jul 21, 2009)

Introduction to graphics and LCD technologies NXP Product Line Microcontrollers, Business Line Standard ICs © February 2009; English; Ordering code: Not Orderable

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Software referenced on this page is provided AS-IS by NXP Semiconductors. NXP Semiconductors does not support or warrant the software contained herein for any purpose other than for informational use.

Microcontrollers selection guide September 2009 The choice for embedded technologies © September 2009; English; Ordering code: 9397 750 16803

	266-MHz ARM9-based MCUs with integrated LCD controller NXP 266-MHz ARM9 microcontroller with integrated LCD controller LH7A40x © June 2007; English; Ordering code: 9397 750 16054
	ARM7 MCU with Ethernet, USB OTG, CAN, and optional LCD controller 72-MHz, 32-bit microcontroller with ARM7TDMI-S™ core LPC24xx © August 2008; English; Ordering code: 9397 750 16574
	ARM7-based MCUs with integrated LCD controller NXP ARM7-based microcontroller with integrated LCD controller LH754xx and LH7952x © June 2007; English; Ordering code: 9397 750 16053
	ARM9 MCUs with up to 256-KB SRAM, Ethernet, USB, and LCD controller NXP 266-MHz, 32-bit ARM926EJ-S processor LPC32x0 © August 2008; English; Ordering code: 9397 750 16605