dsp56k

DSP56K(4)                        Special files                       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 bi-directional handshaked host port.

       To  send  a  data  stream  to  the signal processor, use write() to the
       device, and read() 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()
              argument  must  be a pointer to a struct dsp56k_binary with mem-
              bers 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 zero 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() 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

AUTHORS
       Fredrik Noring <noring@nocrew.org>, lars  brinkhoff  <lars@nocrew.org>,
       Tomas Berndtsson <tomas@nocrew.org>.

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



Linux                             2000-03-01                         DSP56K(4)