Software Compatibility Issues - Motorola MPC860 PowerQUICC User Manual

1.8 Software Compatibility Issues

The following list summarizes the major software differences between the MC68360
QUICC and the MPC860:
¥ Since the MPC860 uses an embedded PowerPC core, code written for the MC68360
must be recompiled for the PowerPC instruction set. Code that accesses MC68360
peripherals requires only minor modiÞcations for use with the MPC860. Although
the functions performed by the PowerQUICC SIU are similar to those performed by
the QUICC SIM, the initialization sequence for the SIU is different and therefore
code that accesses the SIU must be rewritten. Many developers of 68K compilers
now provide compilers that also support the PowerPC architecture.
¥ The addition of the MAC function to the MPC860 CPM block to support the needs
of higher performance communication software is the only major difference
between the CPM on the MC68360 and that on the MPC860. Therefore, the registers
used to initialize the QUICC CPM are similar to the MPC860 CPM, but there are
some minor changes necessary for supporting the MAC function.
When porting code from the MC68360 CPM to the MPC860 CPM, the software writer has
new options for setting hardware break points on CPU commands, address, and serial
request which are useful for software debugging. Support for single-step operation with all
CPM registers visible further simpliÞes software development for the CPM.
MOTOROLA Chapter 1. MPC860 Overview
Part I. Overview
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