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_upload 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 bytes containing zero, 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  ('\0')  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