DSP56K(4)                 (2020-08-13)                  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 comput-
          ers.  The dsp56k special file is used to control the
          DSP56001, and to send and receive data using the bidirec-
          tional 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 quanti-
          ties 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 pro-
               gram, 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.

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     DSP56K(4)                 (2020-08-13)                  DSP56K(4)

          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 quan-
               tities will either truncated, or padded with a null
               byte (aq\0aq) 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 host-
               ing 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, DSP56000/DSP56001 Digital Sig-
          nal Processor User's Manual

     COLOPHON
          This page is part of release 5.10 of the Linux man-pages
          project.  A description of the project, information about
          reporting bugs, and the latest version of this page, can be
          found at https://www.kernel.org/doc/man-pages/.

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