MC68340 datasheet(35/962 Pages) MOTOROLA

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Introduction

MOTOROLA

MC68360 USER’S MANUAL

1-5

1.2.1 CPU32+ Core

The CPU32+ core is a CPU32 that has been modified to connect directly to the 32-bit IMB

and apply the larger bus width. Although the original CPU32 core had a 32-bit internal data

path and 32-bit arithmetic hardware, its interface to the IMB was 16 bits. The CPU32+ core

can operate on 32-bit external operands with one bus cycle. This allows the CPU32+ core

to fetch a long-word instruction in one bus cycle and to fetch two word-length instructions in

one bus cycle, filling the internal instruction queue more quickly. The CPU32+ core can also

read and write 32-bits of data in one bus cycle.

Although the CPU32+ instruction timings are improved, its instruction set is identical to that

of the CPU32. It will also execute the entire M68000 instruction set. It contains the same

background debug mode (BDM) features as the CPU32. No new compilers, assemblers, or

other software support tools need be implemented for the CPU32+; standard CPU32 tools

can be used.

The CPU32+ delivers approximately 4.5 MIPS at 25 MHz, based on the standard (accepted)

assumption that a 10-MHz M68000 delivers 1 VAX MIPS. If an application requires more

performance, the CPU32+ can be disabled, allowing the rest of the QUICC to operate as an

intelligent peripheral to a faster processor. The QUICC provides a special mode called

MC68040 companion mode to allow it to conveniently interface to members of the M68040

family. This two-chip solution provides a 22-MIPS performance at 25 MHz.

The CPU32+ also offers automatic byte alignment features that are not offered on the

CPU32. These features allow 16 or 32-bit data to be read or written at an odd address. The

CPU32+ automatically performs the number of bus cycles required.

1.2.2 System Integration Module (SIM60)

The SIM60 integrates general-purpose features that would be useful in almost any 32-bit

processor system. The term “SIM60” is derived from the QUICC part number, MC68360.

The SIM60 is an enhanced version of the SIM40 that exists on the MC68340 and MC68330

devices.

First, new features, such as a DRAM controller and breakpoint logic, have been added. Sec-

ond, the SIM40 was modified to support a 32-bit IMB as well as a 32-bit external system bus.

Third, new configurations, such as slave mode and internal accesses by an external master,

are supported.

Although the QUICC is always a 32-bit device internally, it may be configured to operate with

a 16-bit data bus. Regardless of the choice of the system bus size, dynamic bus sizing is

supported. Bus sizing allows 8-, 16-, and 32-bit peripherals and memory to exist in the 32-

bit system bus mode and 8- and 16-bit peripherals and memory to exist in the 16-bit system

bus mode.

MC68340 Datasheet(PDF) 35 Page - Motorola, Inc