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MC68349 USER'S MANUAL
MOTOROLA
1.2.2 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 cental
processing unit (CPU) and a peripheral might not be compatible nor run from the same
clock, requiring time delays or other special design considerations.
In an 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.
1.3 CPU030 CENTRAL PROCESSOR UNIT
Processing power for the MC68349 is provided by the CPU030 central processing unit.
The CPU030 delivers 32-bit performance in a modular form factor that is highly optimized
for the needs of portable intelligent personal electronics applications.
The CPU030 employed in the MC68349 is composed of three principle modular elements:
the CPU32+ 32-bit processor, a configurable instruction cache, and a quad data memory
module. Memory management is an option not supported in the MC68349.
1.3.1 CPU32+
The CPU32+ processor is the full 32-bit extension of the CPU32 processor found on many
M68300 family of integrated processors and provides the execution units for the CPU030.
The CPU32+ is a 32-bit execution unit with 32-bit data paths (internal and external), and
has a two-clock basic instruction execution rate for a 32-bit operation. The CPU32+ is
completely upward software compatible with the MC68000 and CPU32.
In addition to performing basic instruction execution, the CPU32+ also supervises power
management capabilities of the MC68349 as well as providing a sophisticated background
debug port for software development and debug environments.