头文件请教
在196中头文件有如下语句:
extern volatile unsigned short register r0; /* 0x0000: R/W */
extern volatile unsigned short register zero_reg; /* 0x0000: R/W */
extern volatile unsigned short register ad_result; /* 0x0002: R */
extern volatile unsigned char register ad_result_lo; /* 0x0002: R */
extern volatile unsigned char register ad_result_hi; /* 0x0003: R */
extern volatile unsigned char register ad_command; /* 0x0002: W */
extern volatile unsigned char register hsi_mode; /* 0x0003: W */
extern volatile unsigned short register hsi_time; /* 0x0004: R */
extern volatile unsigned short register hso_time; /* 0x0004: W */
extern volatile unsigned char register hsi_status; /* 0x0006: R */
extern volatile unsigned char register hso_command;
..
..
为什么这样就可以将特殊功能寄存器定位到从00H开始的地址啊?
发表时间:2005年3月10日10:03:47