Renesas TM V.3.20A Especificaciones descargar pdf (Pagina 74)

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Renesas Technology, Tools FAQs

Last Updated: August 7, 2000

Document Number: 01051251_e

When I declared "const" character string data as the structure, the compiler generated not only constant data but also assembler code

that reserve a ROM area. What is this ROM area for?

The compiler reserves two types of ROM areas: one area for placing constants and one area for placing the address pointer

indicating the constant location start address. The following example shows how the NC30WA compiles the structure.

[Structure Declaration Example]

typedef struct {

uchar SIZE;

uchar far *DATA;

}TEMPLATE;

const TEMPLATE TBL_TEMPLATE[];

const TEMPLATE TBL_TEMPLATE[] = {

{ 2, (uchar far *)"\x10\x04" },

{ 2, (uchar far *)"\x10\x04" }

};

[Structure Data Definition Example]

Character string is placed in a specified area "\x10\x04" at (location).

NC30WA adds the label [___ TO] this address.

Following two types of structure data are placed in the ROM area

These types only repeat the number of the array's elements.

- Constant 2

❍

- Address of character string (the above mentioned "\x10\x04", __TO, which becomes "__TO")❍

Accordingly, { 2, (uchar far *)"\x10\04" }is converted to the following assembly code.

_TBL_MSTEMPLATE:

.byte 02H ;<============== Constant 2 1 byte

.word (___T0)&0FFFFH ;<==== lower 2 bytes of address of letter-string

.word (___T0&0FF0000H)>>16 ;upper 2 bytes of address of letter-string

"\x10\x04" is output at the location indicated by the _TO label.

___T0:

.byte 10H

.byte 04H

.byte 00H ;<== End of character string, NULL is included.

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Renesas TM V.3.20A Especificaciones Pagina 74

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