Building and Optimizing DSP/Bios

Other Parts Discussed in Thread: OMAP-L138

Hi,

We are in a situation where we need to reduce the OS overhead of a many-channel audio application using the DSP side of OMAP-L138. Currently the OS(DSP/BIOS) is taking up 25% of the CPU.

1. Is the DSP/Bios and PSP source code available? We need to full package for rebuilding it.

2. What are the possible bottlenecks we should start with?

Thanks

over 13 years ago

0 Balaji Nagarajan over 13 years ago

TI__Intellectual 1280 points

Hi,

Please refer the below link to download the package:

http://processors.wiki.ti.com/index.php/OMAP-L138_Software_Design_Guide

Topic: RTOS Support for OMAP-L138/C6748

-Thanks,

Balaji N

0 RandyP over 13 years ago in reply to Balaji Nagarajan

TI__Guru* 84110 points

Yan,

You may also want to search the Wiki for "DSP/BIOS source" (no quotes) for information on getting the DSP/BIOS source. You will notice that the license for DSP/BIOS source does not allow for modifications to the source other than for instrumentation.

25% is very high for DSP/BIOS. Are you including the time in PSP drivers in that number, or is it only DSP/BIOS as you said in your post?

Regards,
RandyP

0 Fawad Nackvi62335 over 13 years ago

Expert 1080 points

Yan,

Look at this page http://processors.wiki.ti.com/index.php/Tuning_Audio_Latency_on_C6747

Which is for the L137/C6747. The CPU load is dependent on the buffer size

Buffer Length	Latency (ms)	CPU Load
512	25.8	1.86%
256	14.2	2.46%
128	8.24	4.03%
64	5.4	8.66%
32	3.88	13.3%
16	3.2	25.3%

Can you live with larger buffer sizes and hence higher latency?

I have a 15x9 stereo i2s system which has a load of 7% CPU using buffer size of 128 stereo samples at 48 kHz and a latency of approx 5 milliseconds.

Regards,

Fawad

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Building and Optimizing DSP/Bios