-- 作者:lwlailfg
-- [求助]EM9000 GPIO口的函数调用出错??????
我按照em9000_isa_gpio.pdf中对GPIO口的操作说明在程序中进行操作,编译时出现如下错误:
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
这是什么原因呢?????
当将函数调用处改为:
int PIO_OutEnable(GPIO0); //设置GPIO0 为输出 ///1 int PIO_OutDisable( GPIO1 ); //设置GPIO1 为输入 ///2 int PIO_OutSet(GPIO0 ) ; //GPIO1 输出高电平 ///3 int PIO_OutClear( GPIO0 ); //GPIO0 输出低电平 ///4
编译是可以通过的?????为什么?????
em9000_isa_gpio.pdf中对GPIO口的操作说明:
3、调用EM9000_DIO_Ex.H 中函数操作GPIO 的例子如下:
#define GPIO0 1<<0 #define GPIO1 1<<1
//调用函数 PIO_OutEnable(GPIO0); //设置GPIO0 为输出 ///1 PIO_OutDisable( GPIO1 ); //设置GPIO1 为输入 ///2 PIO_OutSet(GPIO0 ) ; //GPIO1 输出高电平 ///3 PIO_OutClear( GPIO0 ); //GPIO0 输出低电平 ///4
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