_outp, _outpw, _outpd
Outputs a byte (_outp), a word (_outpw), or a double word (_outpd) at a port.
int _outp(
unsigned short port,
int databyte
);
unsigned short _outpw(
unsigned short port,
unsigned short dataword
);
unsigned long _outpd(
unsigned short port,
unsigned long dataword
);
Parameters
port
Port number.databyte, dataword
Output values.
Return Value
The functions return the data output. There is no error return.
Remarks
The _outp, _outpw, and _outpd functions write a byte, a word, and a double word, respectively, to the specified output port. The port argument can be any unsigned integer in the range 0 – 65,535; databyte can be any integer in the range 0 – 255; and dataword can be any value in the range of an integer, an unsigned short integer, and an unsigned long integer, respectively.
Because these functions write directly to an I/O port, they cannot be used in user code in Windows NT, Windows 2000, Windows XP, and Windows Server 2003. For information about using I/O ports in these operating systems, search for "Serial Communications in Win32" at MSDN.
Requirements
Routine |
Required header |
|---|---|
_outp |
<conio.h> |
_outpw |
<conio.h> |
_outpd |
<conio.h> |
For more compatibility information, see Compatibility in the Introduction.
Libraries
All versions of the C run-time libraries.