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Post By：2013-3-18 9:25:00 [顯示全部帖子]
我按照em9000_isa_gpio.pdf中對GPIO口的操作說明在程序中進行操作，編譯時出現如下錯誤：
error LNK2019: unresolved external symbol "int __cdecl PIO_OutClear(unsigned short)" (?PIO_OutClear@@YAHG@Z) referenced in function WinMain
error LNK2019: unresolved external symbol "int __cdecl PIO_OutSet(unsigned short)" (?PIO_OutSet@@YAHG@Z) referenced in function WinMain
error LNK2019: unresolved external symbol "int __cdecl PIO_OutEnable(unsigned short)" (?PIO_OutEnable@@YAHG@Z) referenced in function WinMain
error LNK2019: unresolved external symbol "int __cdecl PIO_OutDisable(unsigned short)" (?PIO_OutDisable@@YAHG@Z) referenced in function WinMain
ARMV4IDbg/shangweiji.exe : fatal error LNK1120: 4 unresolved externals
這是什么原因呢？？？？？
當將函數調用處改為：
int PIO_OutEnable（GPIO0）; //設置GPIO0 為輸出 ///1
int PIO_OutDisable( GPIO1 ); //設置GPIO1 為輸入 ///2
int PIO_OutSet(GPIO0 ) ; //GPIO1 輸出高電平 ///3
int PIO_OutClear（ GPIO0 ）; //GPIO0 輸出低電平 ///4
編譯是可以通過的？？？？？為什么？？？？？
em9000_isa_gpio.pdf中對GPIO口的操作說明：
3、調用EM9000_DIO_Ex.H 中函數操作GPIO 的例子如下：
#define GPIO0 1<<0
#define GPIO1 1<<1
//調用函數
PIO_OutEnable（GPIO0）; //設置GPIO0 為輸出 ///1
PIO_OutDisable( GPIO1 ); //設置GPIO1 為輸入 ///2
PIO_OutSet(GPIO0 ) ; //GPIO1 輸出高電平 ///3
PIO_OutClear（ GPIO0 ）; //GPIO0 輸出低電平 ///4
