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dsp/bios

Started by Medris March 21, 2006
Hi, 
is there any different in cpu time using dsp/bios and without in real-time
and the code is same.

Medris 
Medris wrote:
> Hi, > is there any different in cpu time using dsp/bios and without in real-time > and the code is same.
How can the code be the same with and without BIOS support? Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Medris wrote:
> Hi, > is there any different in cpu time using dsp/bios and without in real-time > and the code is same.
Use of the DSP/BIOS will consume processor resources. The figure I have read is that in general use of an RTOS, such as the DSP/BIOS will add about 5% to the processor load. However, use of a pre-emtive scheduler such as the DSP/BIOS can help to ensure that your application meets its "real time" demands, even though the scheduler requires resources itself. This can be accomplished because the scheduler WILLl execute the highest priority task that CAN be executed and your real time tasks SHOULD be higher priority than ones that are not time critical. What this means is that your application can be designed so that it isn't busy waiting or performing non time critical tasks when a time critical operation is capable of and needs to be performed.
Medris wrote:
> Hi, > is there any different in cpu time using dsp/bios and without in real-time > and the code is same. > > Medris
If your code makes no use of operating system services, and operates as the only process in the system, the run time impact will be minimized. At a programmable "tick rate", the OS will interrupt your code, do some housekeeping, and return to your code. The difference in CPU time depends on how time consuming the housekeeping is and on the tick rate. But if you are using an OS, then you probably want it to actually do something. John
In article <1142964756.044294.226380@g10g2000cwb.googlegroups.com>, "Noway2" <no_spam_me2@hotmail.com> wrote:
> >Use of the DSP/BIOS will consume processor resources. The figure I >have read is that in general use of an RTOS, such as the DSP/BIOS will >add about 5% to the processor load. >
I think this number is a little high. In the sloooooow old days, this would have been an upper limit on a practical system. Processors have gotten faster which reduces the amount of time executing the OS code since most of what is needed from the operating system hasn't changed that much. IMHO YMMV