((unsigned char volatile code *) 0) 解析

#define CBYTE ((unsigned char volatile code *) 0)

#define DBYTE ((unsigned char volatile data *) 0)

#define PBYTE ((unsigned char volatile pdata *) 0)

#define XBYTE ((unsigned char volatile xdata *) 0)

#define CBYTE ((unsigned char volatile code  *) 0)
考虑下这个define定义的内容
1、把CBYTE定义成一个0(0);
2、这个0是个地址(*号);
3、这个地址是代码段的地址(code);
4、并是unsigned char类型的地址(unsigned char);
5、并这个地址的内容是易逝性的(volatile);

unsigned char value;

value = CBYTE[0x02]; // value = *(CBYTE+0x02);