dsp56k(4) [linux man page]

DSP56K(4)						     Linux Programmer's Manual							 DSP56K(4)

NAME

       dsp56k - DSP56001 interface device

SYNOPSIS

       #include <asm/dsp56k.h>

       ssize_t read(int fd, void *data, size_t length);
       ssize_t write(int fd, void *data, size_t length);

       int ioctl(int fd, DSP56K_UPLOAD, struct dsp56k_upload *program);
       int ioctl(int fd, DSP56K_SET_TX_WSIZE, int wsize);
       int ioctl(int fd, DSP56K_SET_RX_WSIZE, int wsize);
       int ioctl(int fd, DSP56K_HOST_FLAGS, struct dsp56k_host_flags *flags);
       int ioctl(int fd, DSP56K_HOST_CMD, int cmd);

CONFIGURATION

       The dsp56k device is a character device with major number 55 and minor number 0.

DESCRIPTION

       The  Motorola  DSP56001	is a fully programmable 24-bit digital signal processor found in Atari Falcon030-compatible computers.	The dsp56k
       special file is used to control the DSP56001, and to send and receive data using the bidirectional handshaked host port.

       To send a data stream to the signal processor, use write(2) to the device, and read(2) to receive processed data.  The data can be sent	or
       received in 8, 16, 24, or 32-bit quantities on the host side, but will always be seen as 24-bit quantities in the DSP56001.

       The following ioctl(2) calls are used to control the dsp56k device:

       DSP56K_UPLOAD
	      resets the DSP56001 and uploads a program.  The third ioctl(2) argument must be a pointer to a struct dsp56k_binary with members bin
	      pointing to a DSP56001 binary program, and len set to the length of the program, counted in 24-bit words.

       DSP56K_SET_TX_WSIZE
	      sets the transmit word size.  Allowed values are in the range 1 to 4, and is the number of bytes that will be sent at a time to  the
	      DSP56001.   These  data  quantities  will either be padded with zero bytes, or truncated to fit the native 24-bit data format of the
	      DSP56001.

       DSP56K_SET_RX_WSIZE
	      sets the receive word size.  Allowed values are in the range 1 to 4, and is the number of bytes that will be received at a time from
	      the  DSP56001.   These data quantities will either truncated, or padded with a null byte ('') to fit the native 24-bit data format
	      of the DSP56001.

       DSP56K_HOST_FLAGS
	      read and write the host flags.  The host flags are four general-purpose bits that can be read by both the hosting computer  and  the
	      DSP56001.  Bits 0 and 1 can be written by the host, and bits 2 and 3 can be written by the DSP56001.

	      To  access the host flags, the third ioctl(2) argument must be a pointer to a struct dsp56k_host_flags.  If bit 0 or 1 is set in the
	      dir member, the corresponding bit in out will be written to the host flags.  The state of all host flags will  be  returned  in  the
	      lower four bits of the status member.

       DSP56K_HOST_CMD
	      sends  a host command.  Allowed values are in the range 0 to 31, and is a user-defined command handled by the program running in the
	      DSP56001.

FILES

       /dev/dsp56k

SEE ALSO

       linux/include/asm-m68k/dsp56k.h, linux/drivers/char/dsp56k.c, http://dsp56k.nocrew.org/, DSP56000/DSP56001 Digital Signal Processor  User's
       Manual

COLOPHON

       This  page is part of release 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

Linux								    2000-03-01								 DSP56K(4)

Check Out this Related Man Page

IOCTL(2)						     Linux Programmer's Manual							  IOCTL(2)

NAME

       ioctl - control device

SYNOPSIS

       #include <sys/ioctl.h>

       int ioctl(int d, int request, ...);

DESCRIPTION

       The ioctl() function manipulates the underlying device parameters of special files.  In particular, many operating characteristics of char-
       acter special files (e.g., terminals) may be controlled with ioctl() requests.  The argument d must be an open file descriptor.

       The second argument is a device-dependent request code.	The third argument is an untyped pointer to memory.  It's traditionally char *argp
       (from the days before void * was valid C), and will be so named for this discussion.

       An  ioctl() request has encoded in it whether the argument is an in parameter or out parameter, and the size of the argument argp in bytes.
       Macros and defines used in specifying an ioctl() request are located in the file <sys/ioctl.h>.

RETURN VALUE

       Usually, on success zero is returned.  A few ioctl() requests use the return value as an output parameter and return a nonnegative value on
       success.  On error, -1 is returned, and errno is set appropriately.

ERRORS

       EBADF  d is not a valid descriptor.

       EFAULT argp references an inaccessible memory area.

       EINVAL Request or argp is not valid.

       ENOTTY d is not associated with a character special device.

       ENOTTY The specified request does not apply to the kind of object that the descriptor d references.

CONFORMING TO

       No  single  standard.   Arguments, returns, and semantics of ioctl() vary according to the device driver in question (the call is used as a
       catch-all for operations that don't cleanly fit the UNIX stream I/O model).  See ioctl_list(2) for a list of  many  of  the  known  ioctl()
       calls.  The ioctl() function call appeared in Version 7 AT&T UNIX.

NOTES

       In  order to use this call, one needs an open file descriptor.  Often the open(2) call has unwanted side effects, that can be avoided under
       Linux by giving it the O_NONBLOCK flag.

SEE ALSO

       execve(2), fcntl(2), ioctl_list(2), open(2), sd(4), tty(4)

COLOPHON

       This page is part of release 3.44 of the Linux man-pages project.  A description of the project, and information about reporting bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

Linux								    2000-09-21								  IOCTL(2)

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dsp56k(4) [linux man page]

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