【免费】C与汇编的混合编程说明资源-CSDN文库

C与汇编的混合编程说明

需积分: 0 93 浏览量 2009-02-23 10:35:15 上传评论收藏 169KB PDF 举报

资源详情

资源评论

Application Note

SLAA140 – March 2002

Mixing C and Assembler With the MSP430

Stefan Schauer MSP430

ABSTRACT

This application note describes how C and assembler code can be used together within

an MSP430 application. The combination of C and assembler benefits the designer by

providing the power of a high-level language as well as the speed, efficiency, and low-

level control of assembler.

Contents

1 Definition of the IAR C-Compiler for Passing Variables Between Functions ...........................2

2 Requirements of Assembler Routines to Support Being Called From C..................................3

3 Combining C and Assembler Functions .....................................................................................4

4 Building Libraries .........................................................................................................................6

5 Using Watch Windows With Assembler Variables .....................................................................8

Figures

Figure 1.Parameter Passing From C ..................................................................................................2

Tables

Table 1. Location of Passed Parameters...........................................................................................3

SLAA140.

4 Mixing C and Assembler With the MSP430

If the C code is compiled with -ur45, but the application is not to run in the ROM monitor, then it

is possible to use R4 and R5 in the assembler routine without saving them, since the C code

never uses them.

2.2 Interrupt Functions

The calling convention cannot be used for interrupt functions, since the interrupt may occur

during the calling of a foreground function. Hence, the requirements for an interrupt function

routine are different from those of a normal function routine as follows:

• The routine must preserve all used registers, including scratch registers R12–R15.

• The routine must exit using RETI.

• The routine must treat all flags of the status register as undefined (Carry / Neg. / Zero /

Overflow).

2.3 Defining Interrupt Vectors

As an alternative to defining a C interrupt function in assembly language as described above, the

user is free to assemble an interrupt routine and install it directly in the interrupt vector.

The interrupt vectors are located in the INTVEC segment.

3 Combining C and Assembler Functions

3.1 General Basics

The mechanics to combine C and assembler functions are fairly straightforward. Basically C

code within .c files imports labels exported by the assembler files using the extern keyword.

Assembler codes within .s43 files export labels to the C code using the PUBLIC keyword.

Assembler code import labels exported by C code using the EXTERN keyword. No keyword is

required to export C labels to assembler code.

Once the .c and .s43 files are written, they are added to the workbench project and the project is

built. See the example .c, .s43, and project (.prj) files included with this application note. See the

IAR documentation for a more complete description of this process.

3.2 Calling Assembler Functions Without Parameters to Pass

If no parameters have to be passed between the C code and the assembler function, a simple

call instruction can be used. See example 1.

3.3 Calling Assembler Functions With Parameters to Pass

When it is required to pass parameters from C to the assembler function, the parameters must

be located as described in the Stack Frames and Parameter Passing section.

Example 2 shows how parameters are passed between the C main program and an assembler

function.

剩余20页未读，继续阅读

评论收藏

内容反馈

C与汇编的混合编程说明

评论0

最新资源

C与汇编的混合编程说明

评论0

最新资源

相关推荐

Keil中C与汇编混合编程的方法

c语言和汇编混合编程

iar_stm8_c语言与汇编混合编程

C语言与汇编语言混合编程

C语言与汇编混合编程机理探析与应用.pdf

keilC语言与汇编语言的混合编程方法.pdf

C语言与汇编语言混合编程浅析

单片机 C与汇编混合编程

单片机C语言和汇编语言混合编程实例详解-杜树春.rar

CCS集成环境下C与汇编的混合编程实现

DSP C与汇编混合编程简单例子

keil_C语言与汇编语言的混合编程方法

单片机C语言与汇编混合编程.PDF

ARM汇编语言与嵌入式C语言混合编程内嵌汇编.pdf

C语言与汇编的混合编程

C语言和汇编语言的混合编程

avr中嵌入汇编 iar中c与汇编混合编程

单片机C语言和汇编语言混合编程实例详解

基于单片机的C语言与汇编语言的混合编程.pdf

keil中c 跟汇编混合编程

MSP430单片机C语言和汇编语言混合编程

单片机C语言与汇编语言混合编程

关于c与汇编混合编程的一点总结

c语言和汇编语言混合编程实例详解.rar

单片机c语言和汇编语言混合编程实例

第6章 C语言和汇编语言混合编程(C55x DSP)

串口助手工具合集.zip

OLED显示温度和时间-STM32F103C8T6（完整程序工程+原理图+相关资料）.zip