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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 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 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