CPU16
REFERENCE MANUAL
COMPARISON OF CPU16/M68HC11 CPU ASSEMBLY LANGUAGE
For More Information On This Product,
Go to: www.freescale.com
MOTOROLA
A-1
APPENDIX A COMPARISON OF CPU16/M68HC11 CPU ASSEMBLY
LANGUAGE
A.1 Introduction
This appendix compares the assembly language of the M68HC11 microcontroller and
the M68HC16 microcontroller. It provides information concerning functionally equiva-
lent instructions and discusses cases that need special attention. It is intended to sup-
plement the CPU16 Reference Manual — refer to appropriate sections of the manual
for detailed information on system resources, addressing modes, instruction set, and
processing flow.
The appendix is divided into eight sections. The first section shows M68HC11 CPU
and CPU16 register models. The second discusses CPU16 instruction formats and
pipelining. The third lists M68HC11 CPU instructions that have an equivalent CPU16
instruction. The fourth lists M68HC11 CPU instructions that operate differently on the
CPU16. The fifth lists M68HC11 CPU assembler directives that operate differently on
the CPU16, but for which the difference is transparent to the programmer. The sixth
lists directives that have a new syntax. The seventh section discusses changes to
addressing modes. The last section is an assembly language comparison in tabular
format.
The CPU16 is designed for maximum compatibility with the M68HC11 CPU, and only
moderate effort is required to port an application from an M68HC11 microcontroller to
an M68HC16 microcontroller. Certain M68HC11instructions have been modified to
support the improved addressing and exception handling capabilities of the CPU16.
Other M68HC11 CPU instructions, particularly those related to manipulation of the
condition code register, have been replaced.
F
Freescale Semiconductor, Inc.
n
.