MOTOROLA

MC68340 PRODUCT INFORMATION

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M68300 FAMILY

The MC68340 is one of a series of components in Motorola's M68300 Family. Other members of the family

include the MC68302, MC68330, MC68331, MC68332, and MC68F333.

ORGANIZATION

The M68300 family of integrated processors and controllers is built on an M68000 core processor, an on-

chip bus, and a selection of intelligent peripherals appropriate for a set of applications. The CPU32 is a

powerful central processor with nearly the performance of the MC68020. A system integration module

incorporates the external bus interface and many of the smaller circuits that typically surround a

microprocessor for address decoding, wait-state insertion, interrupt prioritization, clock generation,

arbitration, watchdog timing, and power-on reset timing.

Each member of the M68300 family is distinguished by its selection of peripherals. Peripherals are chosen

to address specific applications but are often useful in a wide variety of applications. The peripherals may be

highly sophisticated timing or protocol engines that have their own processors, or they may be more

traditional peripheral functions, such as UARTs and timers. Since each major function is designed in a

standalone module, each module might be found in many different M68300 family parts. Driver software

written for a module on one M68300 part can be used to run the same module that appears on another part.

ADVANTAGES

By incorporating so many major features into a single M68300 family chip, a system designer can realize

significant savings in design time, power consumption, cost, board space, pin count, and programming. The

equivalent functionality can easily require 20 separate components. Each component might have 16–64

pins, totaling over 350 connections. Most of these connections require interconnects or are duplications.

Each connection is a candidate for a bad solder joint or misrouted trace. Each component is another part to

qualify, purchase, inventory, and maintain. Each component requires a share of the printed circuit board.

Each component draws power—often to drive large buffers to get the signal to another chip. The cumulative

power consumption of all the components must be available from the power supply. The signals between

the CPU and a peripheral might not be compatible nor run from the same clock, requiring time delays or

other special design considerations.

In a M68300 family component, the major functions and glue logic are all properly connected internally,

timed with the same clock, fully tested, and uniformly documented. Power consumption stays well under a

watt, and a special standby mode drops current well under a milliamp during idle periods. Only essential

signals are brought out to pins. The primary package is the surface-mount quad flat pack for the smallest

possible footprint; pin grid arrays are also available.

MC68340 SIGNALS

Figure 2 shows the components and signals.