http://linux.cudeso.be/linuxdoc/snort.php
...
Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Reply by Vladimir Vassilevsky●March 12, 20072007-03-12
dew wrote:
> hi
> i would like to know if a digital signal processor can be used to
> implement string matching algorithms?like boyer moore, etc..or what is
> the equivalent that i used for string matching on ADSP processor
> Thanks
You can implement any algorithm on the general purpose DSP. However
using DSP for the string manipulation is generally not a good idea.
Most of the DSPs can't directly manipulate with bytes; the minimum unit
is word. The address space is limited, and there can be many other
architectural limitations. This will result in a huge and slow code.
Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com
Reply by Ben Bradley●March 11, 20072007-03-11
On 11 Mar 2007 11:38:10 -0700, "dew" <ame2005@gmail.com> wrote:
>On Mar 11, 11:36 pm, "dew" <ame2...@gmail.com> wrote:
>> On Mar 11, 8:55 pm, Jerry Avins <j...@ieee.org> wrote:
>>
>>
>>
>> > dew wrote:
>> > > hi
>> > > i would like to know if a digital signal processor can be used to
>> > > implement string matching algorithms?like boyer moore, etc..or what is
>> > > the equivalent that i used for string matching on ADSP processor
>> > > Thanks
>>
>> > DSP chips' CPUs are optimized for processing digital data in several
>> > ways. Their peripheral devices, off-chip access standards, interrupt
>> > structures, and more are likewise specialized. Nevertheless, they can
>> > compute any algorithm so long as code and data both fit into available
>> > memory.
>>
>> > I'm curious: what string-matching application would be well served by a
>> > processor specialized for -- and perhaps encumbered with -- other uses?
>>
>> > Jerry
>> > --
>> > Engineering is the art of making what you want from things you can get.
>> > �����������������������������������������������������������������������
>>
>> Thank you for the reply.I am actually jus experimenting with snort
>> IDS.
Snort IDS? What is that?
>> and have been trying to see if the pattern matching module can be
>> implemented on hardware.besides,(obvious from my question) that i am a
>> newbie in DSP, have been trying to find out from the web how string
>> manipulation and matching will take place on a DSP.Thanks a lot for
>> the reply
>
>Are there any resources for me to start with about DSP string
>processing,etc.
If you're looking to do things in the C the standard C-language
string.h header file, DSP's can generally do it (because there are C
compilers for most all DSP's), but there is no special hardware for
string processing in DSP's, and they would do it no better than
standard, "mainstream" processors. If text string processing is the
only "special" thing the processor would be doing, you would probably
be better off using a "standard" processor.
If this has something to do with optical character recognition
(OCR), then that's another matter, but I still offhand don't see where
DSP would have a particular advantage over standard processing.
Reply by julius●March 11, 20072007-03-11
On Mar 11, 1:38 pm, "dew" <ame2...@gmail.com> wrote:
>
> Are there any resources for me to start with about DSP string
> processing,etc.
What do you mean by "DSP string processing"?
Just to clarify a bit, what people call "DSP chips" come with
dedicated hardware to do vector multiplication and convolution
efficiently and quickly. In order to do so, they typically have
a pipelined architecture. This means that they are meant to do
vector multiplication and convolution on fairly long vectors
or signals. This means that they are not well-suited for
executing logical decision-making, because of the pipelining.
Like Jerry said, it does not mean that it's not possible, but
you're better off using a general processor.
So if your "string processing" includes many vector multiplies
and convolution, great. If you are thinking "string processing"
as in "string matching", you're looking in the wrong place.
Hope that helps,
Julius
Reply by Jerry Avins●March 11, 20072007-03-11
dew wrote:
> On Mar 11, 8:55 pm, Jerry Avins <j...@ieee.org> wrote:
...
>> I'm curious: what string-matching application would be well served by a
>> processor specialized for -- and perhaps encumbered with -- other uses?
> Thank you for the reply.I am actually jus experimenting with snort
> IDS.and have been trying to see if the pattern matching module can be
> implemented on hardware.besides,(obvious from my question) that i am a
> newbie in DSP, have been trying to find out from the web how string
> manipulation and matching will take place on a DSP.Thanks a lot for
> the reply
DSPs are complete Turing equivalents and can run any algorithm, as I
wrote. They often run without an operating system and rarely have hard
disks. They are almost always embedded in such specialized devices as
modems, cell phones, and power-line monitors. It is not the instruction
set that constrains what it is reasonable to run on them, but their
operating environment.
Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Reply by dew●March 11, 20072007-03-11
On Mar 11, 11:36 pm, "dew" <ame2...@gmail.com> wrote:
> On Mar 11, 8:55 pm, Jerry Avins <j...@ieee.org> wrote:
>
>
>
> > dew wrote:
> > > hi
> > > i would like to know if a digital signal processor can be used to
> > > implement string matching algorithms?like boyer moore, etc..or what is
> > > the equivalent that i used for string matching on ADSP processor
> > > Thanks
>
> > DSP chips' CPUs are optimized for processing digital data in several
> > ways. Their peripheral devices, off-chip access standards, interrupt
> > structures, and more are likewise specialized. Nevertheless, they can
> > compute any algorithm so long as code and data both fit into available
> > memory.
>
> > I'm curious: what string-matching application would be well served by a
> > processor specialized for -- and perhaps encumbered with -- other uses?
>
> > Jerry
> > --
> > Engineering is the art of making what you want from things you can get.
> > =AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=
>
> Thank you for the reply.I am actually jus experimenting with snort
> IDS.and have been trying to see if the pattern matching module can be
> implemented on hardware.besides,(obvious from my question) that i am a
> newbie in DSP, have been trying to find out from the web how string
> manipulation and matching will take place on a DSP.Thanks a lot for
> the reply
Are there any resources for me to start with about DSP string
processing,etc.
Reply by dew●March 11, 20072007-03-11
On Mar 11, 8:55 pm, Jerry Avins <j...@ieee.org> wrote:
> dew wrote:
> > hi
> > i would like to know if a digital signal processor can be used to
> > implement string matching algorithms?like boyer moore, etc..or what is
> > the equivalent that i used for string matching on ADSP processor
> > Thanks
>
> DSP chips' CPUs are optimized for processing digital data in several
> ways. Their peripheral devices, off-chip access standards, interrupt
> structures, and more are likewise specialized. Nevertheless, they can
> compute any algorithm so long as code and data both fit into available
> memory.
>
> I'm curious: what string-matching application would be well served by a
> processor specialized for -- and perhaps encumbered with -- other uses?
>
> Jerry
> --
> Engineering is the art of making what you want from things you can get.
> =AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=
=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=
=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF
Thank you for the reply.I am actually jus experimenting with snort
IDS.and have been trying to see if the pattern matching module can be
implemented on hardware.besides,(obvious from my question) that i am a
newbie in DSP, have been trying to find out from the web how string
manipulation and matching will take place on a DSP.Thanks a lot for
the reply
Reply by Jerry Avins●March 11, 20072007-03-11
dew wrote:
> hi
> i would like to know if a digital signal processor can be used to
> implement string matching algorithms?like boyer moore, etc..or what is
> the equivalent that i used for string matching on ADSP processor
> Thanks
DSP chips' CPUs are optimized for processing digital data in several
ways. Their peripheral devices, off-chip access standards, interrupt
structures, and more are likewise specialized. Nevertheless, they can
compute any algorithm so long as code and data both fit into available
memory.
I'm curious: what string-matching application would be well served by a
processor specialized for -- and perhaps encumbered with -- other uses?
Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯