Originální popis anglicky:
dsp56k - DSP56001 interface device
Návod, kniha: Linux Programmer's Manual
#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);
The dsp56k device is a character device with major number 55 and minor number 0.
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
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 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.
/dev/dsp56k
Fredrik Noring <noring@nocrew.org>, lars brinkhoff
<lars@nocrew.org>, Tomas Berndtsson <tomas@nocrew.org>.
linux/include/asm-m68k/dsp56k.h, linux/drivers/char/dsp56k.c,
http://dsp56k.nocrew.org/, DSP56000/DSP56001 Digital Signal Processor User's
Manual
