AN1218 datasheet(2/56 Pages) FREESCALE

2 / 56 page

Application Note

AN1218 Rev. 2

This application note will help inform and educate the reader concerning

the differences between the HC05 and HC08 CPUs. Detailed examples

illustrating the added features found with the CPU08 are given to help

optimize software design with the CPU08.

Scope of this Application Note

This note assumes the reader has a background in MCU software and

hardware design and is also familiar with the HC05. It was written for the

engineering manager and the design engineer. As a reference, the

application note overviews the basic differences between the two CPUs

so that one can fit the right CPU for a specific application. As a tutorial,

the application note gives the designer the means to understand and

utilize the HC08 enhancements. Software is given to illustrate and

compare the performance of the CPUs.

HC08 Features

The following is a list of major features of the HC08 CPU (CPU08) that

differentiate it from the HC05 CPU (CPU05).

• Fully upward object code compatible with the MC6805,

MC146805, and the MC68HC05 Family

• 64 KByte program/data memory space

• Enhanced HC05 programming model

• 8 MHz CPU bus frequency

• 16 addressing modes, 5 more than the HC05

• Expandable internal bus definition for addressing range extension

beyond 64 KBytes

• 16-bit index register with manipulation instructions

• 16-bit stack pointer with manipulation instructions

• Memory to memory data moves without using the accumulator

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

AN1218 Folha de dados(PDF) 2 Page - Freescale Semiconductor, Inc