混合编程问题

jhw3378

混合编程问题 [复制链接]

//主程序
#include "msp430x44x.h"
extern cheng
//====================================
   NAME  main
   ORG 0FFFEh
   DW RESET
//---------------------------------
   RSEG  CSTACK
   RSEG  CODE
;---------------------------------
RESET mov.w #SFE(CSTACK),SP;CSTACK=0200-0A00
main  mov.w #WDTPW+WDTHOLD,&WDTCTL
//-------------------------------------
   mov.w #20,R14;
   mov.w #40,R12;
   call #cheng//结果在R12
//-------------------------------------
main1
   jmp main1
//--------------------------------
   END

//子程序
#include "msp430x44x.h"
//extern unsigned int ?Mul16Hw(unsigned int,unsigned int);
unsigned int cheng(unsigned int i1,unsigned int i2)
{
return(i1*i2);
}

错误提示：
//Error[e46]: Undefined external "?Mul16Hw" referred in chengc

如何解决