Embedded Intel386™ Microprocessors Family Product Brief/Linecard

Product Overview Time to Market 186 Upgrade Processor Low-Voltage Operation Power and System Management System Form Factor Development Tools

Product Overview
The Intel386™ CX, DX, EX, and SX embedded processors are based on the Intel386 architecture. All have 32-bit cores, and enhanced functionality for the embedded processor market.

• The static Intel386 EX microprocessor is designed for embedded applications that require high integration and low power. Key features include: PC compatibility, power management, low-voltage operation, and on-chip integration of numerous common peripherals such as interrupt controllers, chip selects, counters and timers.
• The static Intel386 CX microprocessor is designed for low power environments. With its clock freeze mode, low-voltage operation, and static core, it functions in a very low power environment. It has a 26-bit external address bus and can address 64 megabytes of physical memory.
• The static Intel386 SX microprocessor is a pin-for-pin replacement for the dynamic Intel386 SX processor. The static design features clock freeze mode, and higher speed operation.
• The dynamic Intel386 SX microprocessor is an entry-level processor with a 16-bit external data bus and a 24-bit external address bus. It provides the performance benefits of a 32-bit architecture with the cost savings of a 16-bit hardware system.
• The dynamic Intel386 DX microprocessor is designed for single-user, multi-tasking applications. The 32-bit registers and data paths support 32-bit addresses and data types. It addresses 4 gigabytes of physical memory, and 64 terabytes of virtual memory. It offers a 50%1 performance increase over the Intel386 CX, EX and SX processors.

Embedded system designers have long understood the benefits of PC compatibility in their designs. The embedded Intel386 processors are compatible with DOS and standard graphical windowing operating environments, as well as many popular embedded real-time operating systems. This opens many new opportunities for embedded system designers.

Applications based on Intel architecture have a solid future. The Intel 186/188 family of products have been accepted in a broad range of applications, with over ten thousand design wins and over fifty million units shipped during the past decade. This legacy, coupled with upgrade paths to Intel386 and Intel486™ microprocessors, ensures a clear path for future designs.

Applications based on an Intel386 microprocessor become more user-friendly. Embedding popular versions of DOS and popular graphical windowing environments allows designers to implement an array of existing software applications within their systems. In fact, software packages traditionally used in personal computers, such as Lotus 1-2-3* and Microsoft* Excel, are now finding their way into embedded solutions.

The PC compatibility, enhanced functionality, and real-time software support make the Intel386 microprocessors an excellent embedded solution. Reduced design complexity and decreased software development time are major advantages in today's embedded market.

Time to Market
In the embedded environment, reduced time to market is a competitive advantage. The embedded Intel386 processors reduce time to market by shortening both software and hardware design cycles.

By using a processor based on the Intel architecture, designers reduce their code development time. With over 50,000 DOS-based applications available today, there is a substantial possibility of reducing software development time. There are other operating systems designed for the PC environment, including real-time operating systems, and standard windowing environments. Designers can avoid developing proprietary operating systems for their embedded applications. With the enormous software library for the DOS environment, real-time and popular windowing operating systems, BIOS-level routines, and device drivers, designers can substantially decrease code development and debugging time.

The embedded Intel386 processors preserve investments with existing Intel architecture software. Because the embedded Intel386 CPUs are 100% binary compatible with the 186/188 CPU, upgrading to an Intel386 CPU preserves software investment, and speeds time to market.

The PC makes an excellent tool for debugging code before application hardware is available. Code can be written and debugged in parallel with hardware development. With other architectures, the hardware must be complete before debugging can begin – delaying time to market. The ability to use a PC for software debugging, in addition to a wide selection of development tools, allows for quick, and inexpensive software development.

Designing with the Intel386 microprocessors decreases hardware development time. The Intel architecture is the most widely used architecture in the world. Many designers already have experience designing with the Intel architecture.

Intel386 EX architecture designs are even easier. Many peripheral devices used on a personal computer are integrated on the Intel386 EX chip. To add further value to the system, the Intel386 EX processor implements embedded peripheral functions such as interrupt controllers, chip-select generation, 16-bit timers and counters, DRAM refresh, watchdog timer, serial ports, etc. The high integration of the Intel386 EX microprocessor significantly reduces system complexity and hardware design time.

Integration of the Intel386 EX processor can also provide you with a simplified, compact design that can also lessen your burden on support chips that may become hard to find. This is especially important if your applications must be supported for a long time, whether it is an embedded PC design or a traditional design.

186 Upgrade Processor
Intel's 186 processor family has been designed in many embedded applications over the years. If a 186 embedded design requires either more addressibility or higher performance, the Intel386 EX processor is the upgrade choice. The EX provides 26 address bits for a total of 64 Gbytes. Also, given the same clock rate, the Intel386 EX processor performs up to 3 times the performance over a 186-base processor. Since the EX has an 80386 core, it is code compatible with 186 processors, making it a logical upgrade processor to run your existing software.

Additionally, software can be modified to take advantage of the 80386 features, including memory protection and multitasking. The EX can allow your application to run multiple concurrent tasks that could not be safely done on other microprocessors. Also, memory protection can provide a safety net to software problems. This can become very important if your customer ever modifies the software run on your application.

Low-Voltage Operation
The Intel386 EX and static CX processors are designed to be ideal for portable applications. Low power consumption is critical for these designs. Low-voltage operation offers numerous benefits to the system designer including decreased power consumption, lower heat dissipation and reduced noise generation. See Table 1 for Intel386 microprocessor voltage tolerances and operating frequencies.

Lowering the operating voltage from 5 volts to 3 volts decreases device power consumption by over 60 percent. For battery-operated system, this can translate into a 40 percent decrease in current consumption and at least a 40 percent increase in battery life. Low-voltage operation of the Intel386 EX and CX processors allows designs previously requiring bulky power supplies to become portable, operating on batteries.

Reducing operating voltage reduces the heat generated by a device. Device power consumption varies as the square of operating voltage. Heat generated by a device is a direct result of the power it consumes. Many failure mechanisms in semiconductors are heat related, therefore low-voltage designs are usually more reliable. Devices that produce less heat can operate in higher ambient temperature environments, and can be placed closer together on a printed circuit board, decreasing the form factor and costs.

Low-voltage designs are less noisy. Noise is related to both the voltage swing and the transition time of transistors switching in a device. Because low-voltage devices have decreased voltage swings, they generate less noise. Decreased noise generation is a substantial benefit to applications that are required to comply with noise emission regulations. Low-voltage designs can avoid potentially expensive noise reduction techniques.

Power and System Management
Low-voltage operation is only part of a complete low power solution. To make a true low power device, power management must be implemented. The Intel System Management Mode is built into the Intel386 CX and EX chips.

The Intel System Management Mode (SMM) is typically used to execute specific routines for power management. After entering SMM, various parts of a system can be shut down or disabled to minimize power consumption. SMM operates independently of other system software, and can be used for other purposes too.

Table 1: Voltage Operation At Different Operating Frequencies

FREQUENCY	EXTB	EXTC	CXSA	CXSB	DX	SX	Static SX
16 MHz	-	-	-	3.0V	5.0V	5.0V	-
20 MHz	3.0V	-	-	-	5.0V	5.0V	-
25 MHz	3.3V	5.0V	5.0V	3.3V	5.0V	5.0V	5.0V
33 MHz	-	5.0V	5.0V	3.3V	5.0V	5.0V	5.0V
40 MHz	-	-	5.0V	-	-	-	5.0V

The Intel386 EX processor has a Power Management Unit that offers Idle mode and Powerdown mode. When the Intel386 EX CPU is waiting for an external event to occur, the Idle mode stops the CPU clock, however, all the peripheral clocks are still active. Depending on peripheral utilization, current consumption can be reduced considerably. Powerdown disables the clock to both the CPU core and peripherals. In this mode, current consumption is reduced to a few microamps. The power management modes available on the embedded Intel386 EX microprocessors make it ideal for battery-powered, portable applications.

The Intel386 CX & static SX processors offer clock freeze mode. In this mode, clock input can be stopped and started without losing CPU context. This power saving feature coupled with a static design make these chips ideal for low power environments.

System Form Factor
Portable applications have two major requirements: low power consumption and a small form factor. The Intel386 EX and CX chips meet these requirements. Low power consumption is addressed by low-voltage operation, integrated SMM circuitry, and for the Intel386 EX CPU, power management modes.

The Intel386 EX chip helps reduce system form factor with high integration. Many peripherals required in a PC compatible system are already integrated onto the Intel386 EX chip, making it ideal for portable, small form factor designs.

System form factor can be reduced with small packaging. The embedded Intel386 chips are available in a Plastic Quad Flat Pack (PQFP). Even smaller, the Intel386 EX processor is available in a Thin Quad Flat Pack (TQFP) and the Intel386 CX CPU is available in a Shrink Quad Flat Pack (SQFP). Intel can provide these chips as unpackaged die for even further size reductions. Using these in conjunction with other devices in advanced surface-mount packages, such as SSOP and TSSOP, greatly reduces system form factor. See Table 2 for packaging details.

Development Tools
Embedded systems developers can now take advantage of the tremendous number of tools developed for the PC industry. The embedded Intel386 processors' compatibility with the PC architecture provides access to familiar, low-cost development tools.

Many development tools have been adopted for the embedded environment. These include tools that have been specifically designed for the embedded Intel386 processor family. These include: popular 16 & 32-bit compilers, linker/locators, debuggers, in-circuit emulators and logic analyzers. See “Support Tools” Table for a fuller listing.

The embedded Intel386 processor family provides a low-cost development environment. The size and competitive nature of the PC industry has produced tools that are time-proven and low-cost. Furthermore, these tools run on a PC, eliminating the need for expensive workstation-based development tools.

For developing DOS embedded applications, there are ROMable versions of DOS and BIOS. For non-DOS applications, there exists numerous development tools and operating systems for multi-tasking, real-time, and 32-bit applications.

The familiar, cost effective development environment of the embedded Intel386 processors allow embedded system developers to bring products to market more quickly, at a lower cost.

¹Benchmarks based on SpectInt92 results

Clock freeze mode only (1) Asynchronous, (2) Synchronous