man > dsp56k(4)

dsp56k(4)                             Kernel Interfaces 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 re‐
       ceive 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 pro‐
              gram, 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  num‐
              ber  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

Linux man-pages 6.7                          2023-10-31                                    dsp56k(4)