_inpd -- Read Doubleword from Input Port

Format

#include <conio.h>  /* also in <builtin.h> */
unsigned long _inpd(const unsigned int port);

Language Level: Extension
_inpd reads a 4-byte (doubleword) unsigned value from the specified input port. The port number must be an unsigned short value within the range 0 to 65 535 inclusive.

Note: _inpd is a built-in function, which means it is implemented as an inline instruction and has no backing code in the library. For this reason:

You can run code containing this function only at ring zero. Otherwise, an invalid instruction exception is generated.

Return Value
_inpd returns the value read from the specified port. There is no error return value, and _inpd does not set errno.

Example



_inp -- Read Byte from Input Port
_inpw -- Read Unsigned Short from Input Port
isatty -- Test Handle for Character Device
_outp -- Write Byte to Output Port
_outpw -- Write Word to Output Port
_outpd -- Write Double Word to Output Port
<builtin.h>
<conio.h>