ST9 datasheet(112/146 Pages) STMICROELECTRONICS

112 / 146 page

112/146

ST9 USER GUIDE

5 USING THE DEVELOPMENT TOOLS

5.1 DEVELOPING IN C LANGUAGE

Although the ST9 C Compiler is an optional product, you are strongly advised to write your

software using a High Level Language. Naturally for the sake of optimization, especially to ob-

tain the best execution times from certain frequently-used pieces of code, assembly language

will still remain the right choice. This will be true at least for the initialisation file. But writing a

complete program in assembler has few advantages and many drawbacks, so there can be no

economic justification for using only assembler.

This is why some of the examples in this guide are written in assembler and some in C. The

development tools allow you to mix both languages easily.

A useful book, if you have some experience of C language is “The C language”, by Kernighan

and Ritchie, second edition.

5.2 AVAILABLE TOOLS

The following tools are available for the ST9 family:

– A Software development package, named GNU9P, that includes a C-compiler and a Make

utility.

– A range of emulators for the various sub-families.

You have two options in terms of development tool products. A software development

package is delivered with each emulator. This does not include the C-compiler. You must pur-

chase it separately. So with the emulator package alone you can only do assembler program-

ming.

As previously mentioned, you are strongly advised to use C programming as much as pos-

sible, for the obvious reasons of structuring the source code, of code portability and reus-

ability. In addition, developing the program is much easier and more reliable due to the con-

trols and checks performed by the C-compiler.

However, in the event that a program requires very fast processing, the C language is imprac-

tical so the program must be carefully written in assembly language

Another point worth mentioning is the development environment, which is the part of the soft-

ware that deals with the production and the modification of the source files.

ST9 数据表(PDF) 112 Page - STMicroelectronics