One requirement common across a broad span of industrial and general products — from multi-function printers to measurement instruments and through to major home appliances — is for displays that show graphical user interfaces (GUIs) incorporating good information-presentation functions. Users want to be able to acquire operational data quickly and without ambiguity. Further, they value ease of use, which explains why touch panels are being used more frequently. Sophisticated user interfaces are important selling points and there is an ongoing shift to color displays. Screen sizes and resolutions are growing to the extent that some customers now are requesting displays with 1280x1024 SXGA resolution.

The fact that most mass-produced LCD displays are now high-resolution types is helping to drive the trend to higher-resolution graphics in products such as copiers, printers, measurement instruments, and top-end whiteware (for the US market). In turn, this has created a need for more sophisticated image processing, including more requests from system engineers for functions such as alpha-blending (α-blending) and transparency processing for overlaying multiple images, as well as 2D graphics capable of conveying a solid look and feel.

Another typical requirement for today's industrial applications and a growing number of others is for technology for rapidly transferring images across networks. For instance, both graphics and digital communications are vital in applications such as security camera systems, front-door entry-access phones, and digital signage. The necessity to network products and equipment makes it essential that many of the latest microcomputers incorporate a built-in controller for Ethernet or other communication standards.

The factors mentioned above that have driven Renesas to strengthen the range of SuperH microcomputers we offer to customers around the globe. Our newest devices and complete design solutions offer good graphics capabilities and deliver fast, reliable connectivity via industry-standard formats.

SuperH microcomputers support diverse graphics requirements and are available with various combinations of performance and functions at price points that make them optimum design choices for many designs for industrial and general market products. The graphics solutions in this popular product line are broadly divided into two categories: controller-based solutions that use the SH-2A core, and processor-based solutions that use the SH-4A core (see Figure 1). Controller-based SuperH systems primarily use the μITRON real-time operating system, whereas processor-based systems tend to use more sophisticated operating systems such as Linux or VxWorks.

Recommended products for controller-based solutions for new designs are the devices in the SH7262/7264 group. They are ideal choices for products such as copiers and printers, among others. A feature of these superscalar SH-2A series 32-bit devices is that they can implement systems that don't require external SDRAM, since they provide up to 1MB of internal SRAM. This memory capacity is sufficient to store two frames of a 480x240-pixel WQVGA screen.

The Video Display Controller 3 (VDC3) built into SH7262/7264 chips can overlay two layers of image data on top of a video signal. This function is linking the internal SRAM by a bus that has a multiplexed configuration. As a result, three image frames can be sent to the VDC3 the same time.

The internal architecture of the microcomputers in the SH7262/7264 group gives these microcomputers both performance and efficiency. They can process display graphics while operating at a relatively low clock frequency of only 144MHz.

Recommended for processor-based solutions for new designs are the devices in the SH7764 group that have a faster (324MHz) superscalar 32-bit SH-4A CPU and a floating-point unit (FPU). They achieve performance levels up to 583 MIPS and 2.3 GFLOPS.

The graphics functions integrated into SH7764 microcomputers include an LCDC display controller and VDC2 video controller, plus a 2D graphics engine. Graphics data is rapidly transported between these internal functions via a dedicated bus. To simplify the design of embedded systems that must transfer image data over networks, the devices provide an Ethernet controller, as well as a USB 2.0 host/function controller for direct transfers between devices. More information about SH7764 chips is contained in the story, "Product Update: Microcomputers with a Dedicated Bus for Display Data."

Besides SH7764 devices, another recently introduced microcomputer we recommend for processor-based solutions for new designs that implement advanced GUIs is the SH-MobileR2R (SH7724). This high-end model has features satisfying nearly all the display requirements likely to be needed for industrial and general products.

The SH-MobileR2R's video processing engine is the powerful VPU5F. The chip also has an extensive array of other peripheral functions, including a 2D graphics engine, JPEG compression and decompression circuit, 24-bit LCD display controller, and a 24-bit audio DSP core. It supports the display of 1280x1024 pixel SXGA images in 24-bit color, and can also display video in 1280x720 resolution.

Systems incorporating cameras are a prime example of applications for which the SH-MobileR2R is an excellent design choice. Figure 2 shows a security camera system with two cameras that boosts the volume of images that can be stored. To do this, the microcomputer's VPU5F transforms the video captured by the cameras into H.264 format and its on-chip JPEG compression/decompression circuit compresses images into JPEG format. Moreover, audio data from the microphones attached to the cameras is compressed for storage by microcomputer's built-in 24-bit audio DSP core.

Anticipating more demand for advanced functions such as 3D graphics and video playback in industrial and general products, Renesas is developing new SuperH microcomputers with appropriately upgraded processing capabilities. To address the rising need for network connectivity, we are developing additional processor-type solutions that implement the widely used Car Area Network (CAN), Ethernet, and USB standards. Other R&D activities include controllers for SD card interfaces (SDIO functions).

Microcomputers with a Dedicated Bus for Display Data

Strengthening the performance of display functions was a key consideration in designing the internal bus configuration of the SH7764. As a result, to handle image data the microcomputer has a dedicated "pixel bus" that can transfer this data at high speed independently of the CPU bus. The pixel bus connects to the VDC2, 2D graphics engine, and external interfaces (see Figure 3) and both it and the CPU bus can operate at up to 108MHz.

The VDC2 display controller can overlay and display up to four frames of full-color images with WVGA resolution (800x480 pixels). It uses 6-bit values for each color component: R, G, and B. This high level of performance is sufficient for a basic car navigation system, for example. The LCDC is not limited just to WVGA, because it can handle resolutions up to 1024x1024 pixels.

The SH7764 microcomputer also incorporates a built-in 2D graphics engine that can perform key types of processing. Among them are anti-aliasing, advanced thick-line drawing operations, and coordinate transformation operations on input vertex coordinates.

A comprehensive set of external interfaces is another feature of the SH7764. Its built-in Ethernet controller supports the MAC (media access controller) layer with a maximum transfer speed of 10/100Mbps. The microcomputer also integrates a host/function controller for the USB 2.0 standard widely used by personal-computer peripherals, digital cameras, and other devices. There is also an on-chip USB controller that supports Hi-Speed mode (up to 480Mbps).