Texas Instruments DM365, User Manual

Page: 42 / 131

Sample Usage
3-8
This function of FC implements a semaphore which goes into pend
state and then the OS switches the task to another non-codec task.
Interrupts from HDVICP to Host ARM926 is used to inform when the
frame processing is done. HDVICP sends interrupt which maps to
INT
No 10 (KALINT9 Video MJCP)
of ARM926 INTC. After receiving this
interrupt, the semaphore on which the codec task was waiting gets
released and the execution resumes after the
HDVICPSYNC_wait()
function.
The following figure explains the interrupt interaction between
application and codec.
Figure 3-5. Interrupt Between Codec and Application.
Framework calls Encoder Init
HOST ARM926 HDVICP
Start frame processing
At the end send interrupt to Host
that it has finished
Inform Host through interrupt
Codec task wakes up to finish end
of frame processing and returns
back to framework
Framework Calls Encode frame
process
HDVICPSYNC_wait() uses to make
the codec task sleep
Pending over
Exit HDVICPSYNC_wait()
Different task running
This interrupt is not
visible to
framework. It
happens inside
codec library
This interrupt
should be serviced
by framework
Codec lib calls HDVICPSYNC_start
to register the ISR with framework
Codec library internally sends
interrupt to HDVICP to start
processing
Codec calls framework
HDVICP_wait()