80 lines
2.5 KiB
Groff
80 lines
2.5 KiB
Groff
.\" $NetBSD: isv.4,v 1.1 2008/04/02 01:34:36 dyoung Exp $
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or
|
|
.\" without modification, are permitted provided that the following
|
|
.\" conditions are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above
|
|
.\" copyright notice, this list of conditions and the following
|
|
.\" disclaimer in the documentation and/or other materials
|
|
.\" provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this
|
|
.\" software must display the following acknowledgement:
|
|
.\" This product includes software developed by the NetBSD
|
|
.\" Foundation, Inc. and its contributors.
|
|
.\" 4. Neither the name of The NetBSD Foundation nor the names of
|
|
.\" its contributors may be used to endorse or promote products
|
|
.\" derived from this software without specific prior written
|
|
.\" permission.
|
|
.\"
|
|
.Dd April 1, 2008
|
|
.Dt isv 4
|
|
.Os
|
|
.Sh NAME
|
|
.Nm isv
|
|
.Nd IDEC Supervision/16 image capture board
|
|
.Sh SYNOPSIS
|
|
.Cd "isv0 at isa? port 0x2f0"
|
|
.Cd "isv0 at isa? port 0x2e0"
|
|
.Cd "isv0 at isa? port 0x3f0"
|
|
.Cd "isv0 at isa? port 0x3e0"
|
|
.Sh DESCRIPTION
|
|
.Pp
|
|
.Nm
|
|
is a driver for the IDEC Supervision/16, an image capture board
|
|
that plugs into a 16-bit ISA bus.
|
|
The IDEC Supervision/16 digitizes an NTSC television signal, storing
|
|
a 512 x 480-pixel, 8-bit grayscale image in its 256kB dynamic RAM array
|
|
every 1/30th of a second.
|
|
The host reads frames from the DRAM using 122881 16-bit I/O reads.
|
|
Reading frames from the Supervision/16 is quite slow:
|
|
after the host reads a 16-bit word from the DRAM, the Supervision/16
|
|
state machine takes approximately 0.5 microseconds to get ready
|
|
for the next read.
|
|
Theoretically, a frame rate of approximately 10 frames per second
|
|
is possible.
|
|
.Nm
|
|
achieves a frame rate of approximately 6 frames per second.
|
|
.Pp
|
|
.Sh SEE ALSO
|
|
.Xr isvctl 8
|
|
.Rs
|
|
.%R Programming the Supervision/16 Image Capture Board
|
|
.%Q IDEC
|
|
.%D circa 1991
|
|
.Re
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
device first appeared in
|
|
.Nx 5.0 .
|
|
.Sh AUTHORS
|
|
The
|
|
.Nm
|
|
driver was written by
|
|
.An David Young Aq dyoung@NetBSD.org .
|
|
.Sh BUGS
|
|
.Pp
|
|
Synchronizing with the hardware and reading frames from it is very
|
|
CPU-intensive.
|
|
.Pp
|
|
.Nm
|
|
will not detect the capture board if it is not attached to an active
|
|
video source.
|
|
To force
|
|
.Nx
|
|
to detect the capture board at any time, re-scan the ISA bus using,
|
|
e.g.,
|
|
.Ic drvctl Fl r Ar isa0 .
|