CC78K0S Datasheet, PDF (21/520 Pages) NEC – C Compiler Ver.1.30 or Later Language

CHAPTER 1 GENERAL
The CC78K0S Series C Compiler is a language processing program which converts a source program written in
the C language for the 78K/0S Series or ANSI-C into machine language. Object files or assembler source files for
the 78K/0S Series can be obtained by using this CC78K0S Series C compiler.
1.1 C Language and Assembly Language
To have a microcontroller do its job, programs and data are necessary. These programs and data must be written
by a human being (programmer) and stored in the memory section of the microcontroller. Programs and data that
can be handled by the microcontroller are nothing but a set or combination of binary numbers called machine
language.
An assembly language is a symbolic language characterized by one-to-one correspondence of its symbolic
(mnemonic) statements with machine language instructions. Because of this one-to-one correspondence, the
assembly language can provide the computer with detailed instructions (for example, to improve I/O processing
speed). However, this means that the programmer must instruct each and every operation of the computer. For this
reason, it is difficult to understand the logic structure of the program at glance and the programmer is likely to make
errors in coding.
High-level languages were developed as substitutes for such assembly languages. The high-level languages
include a language called C, which allows the programmer to write a program without regard to the architecture of the
computer.
As compared with assembly language programs, it can be said that programs written in C have an easy-to-
understand logic structure.
C has a rich set of parts called functions for use in creating programs. In other words, the programmer can write a
program by combining these functions.
C is characterized by its ease of understanding by human beings. However, understanding of languages by the
microcontroller cannot be extended up to a program written in C. Therefore, to have the computer understand the C
language program, another program is required to translate C language statements into the corresponding machine
language instructions. A program that translates the C language into machine language is called a C compiler.
This C compiler accepts C source modules as inputs and generates object modules or assembler source modules
as outputs. Therefore, the programmer can write a program in C and if he or she wishes to instruct the computer up
to details of program execution, the C source program can be modified in assembly language. The flow of translation
by this C compiler is illustrated in Figure 1-1.
User’s Manual U14872EJ1V0UM
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