dsp56k — DSP56001 interface device
#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 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(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
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 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.
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
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