ppi(9) - NetBSD Manual Pages

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PPI(9)                 NetBSD Kernel Developer's Manual                 PPI(9)


NAME

     ppi -- user-space interface to ppbus parallel port


SYNOPSIS

     #include <sys/ioctl.h>
     #include <dev/ppbus/ppi.h>
     #include <dev/ppbus/ppbus_conf.h>


DESCRIPTION

     All I/O on the ppi interface is performed using ioctl() calls.  Each com-
     mand takes a single uint8_t argument, transferring one byte of data.  The
     following commands are available:

     PPIGDATA, PPISDATA
             Get and set the contents of the data register.

     PPIGSTATUS, PPISSTATUS
             Get and set the contents of the status register.

     PPIGCTRL, PPISCTRL
             Get and set the contents of the control register.  The following
             defines correspond to bits in this register.  Setting a bit in
             the control register drives the corresponding output low.
             STROBE
             AUTOFEED
             nINIT
             SELECTIN
             PCD

     PPIGEPP, PPISEPP
             Get and set the contents of the EPP control register.

     PPIGECR, PPISECR
             Get and set the contents of the ECP control register.

     PPIGFIFO, PPISFIFO
             Read and write the ECP FIFO (8-bit operations only).


EXAMPLES

     To present the value 0x5a to the data port, drive STROBE low and then
     high again, the following code fragment can be used:
             int             fd;
             uint8_t val;

             val = 0x5a;
             ioctl(fd, PPISDATA, &val);
             ioctl(fd, PPIGCTRL, &val);
             val |= STROBE;
             ioctl(fd, PPISCTRL, &val);
             val &= ~STROBE;
             ioctl(fd, PPISCTRL, &val);



SEE ALSO

     ioctl(2), atppc(4), io(4), ppbus(4), ppi(4)


HISTORY

     ppi originally appeared in FreeBSD.


AUTHORS

     This manual page is based on the FreeBSD ppi manual page and was updated
     for the NetBSD port by Gary Thorpe.


BUGS

     The inverse sense of signals is confusing.

     The ioctl() interface is slow, and there is no way (yet) to chain multi-
     ple operations together.

     The headers required for user applications are not installed as part of
     the standard system.

NetBSD 7.0                     December 29, 2003                    NetBSD 7.0