Renesas M3T-MR100 Instrukcja Użytkownika Pobierz pdf (Strona 232)

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7.3 Modifying MR100 Startup Program

MR100 comes with two types of startup programs as described below.

• start.a30

This startup program is used when you created a program using the assembly language.

• crt0mr.a30

This startup program is used when you created a program using the C language.

This program is derived from "start.a30" by adding an initialization routine in C language.

The startup programs perform the following:

• Initialize the processor after a reset.

• Initialize C language variables (crt0mr.a30 only).

• Set the system timer.

• Initialize MR100's data area.

Copy these startup programs from the directory indicated by environment variable "LIB100" to the current directory.

If necessary, correct or add the sections below:

• Setting processor mode register

Set a processor mode matched to your system to the processor mode register. (58-60th line in crt0mr.a30)

• Adding user-required initialization program

When there is an initialization program that is required for your application, add it to the 140th line in the C

language startup program (crt0mr.a30).

• Enable the 138th – 139th line in the C language startup program (crt0mr.a30) if standard I/O function is

used.

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