unsigned char volatile xdataCH375_CMD_PORT _at_ 0xBDF1;/* CH375命令端口的I/O地址 */
CH375_CMD_PORT = Data;

方法二：

*((unsigned char xdata *) 0xBDF1) = Data;

類似：DSP2407的頭文件

voatile unsigned int * IMR = (volatile unsigned int *)0x0004;

*IMR = value;