SVR5

outb(D3)

outb -- write a byte to an 8 bit I/O port

Synopsis

   #include <sys/types.h>
   #include <sys/ddi.h>
   #include <sys/f_ddi.h>
   
   void outb(int port, uchar_t data);

Description

The outb( ) function provides a C language interface to the machine instruction that writes a byte to an 8 bit I/O port using the I/O address space instead of the memory address space.

Arguments

port: A valid 8 bit I/O port.
data: The 8 bit value to be written to the port.

Return values

None

Usage

This function should be used instead of the inline.h or inline assembler version by the same name.

Context and synchronization

All contexts.

Hardware applicability

Intel IA-32 compatible platforms

Version applicability

ddi: 1, 2, 3, 4, 5, 5mp, 6, 6mp, 7, 7mp, 7.1, 7.1mp, 8, 8mp

SCO OpenServer ODDI compatibility

outb(D3oddi) provides the same functionality for SCO OpenServer ODDI drivers, but note differences in the casting of the function and arguments and the return values.

DOS systems often issue this function from user-level code. ``Porting DOS inb and outb functionality'' in HDK Technical Reference provides information about how to port such code to SCO OpenServer systems, but this information is generally appropriate for SVR5 systems as well.

References

inb(D3), inl(D3), inw(D3), outl(D3), outw(D3), repinsb(D3), repinsd(D3), repinsw(D3), repoutsb(D3), repoutsd(D3), repoutsw(D3)

``Programmed I/O (PIO)'' in HDK Technical Reference