> Testing with the k10 (phenom-II) cpu in powersave mode (800 MHz) showed > that the encoding required about <3% and decoding <6% of the 800 MHz. > > That is small enough that it just might fit into a Cortex-M4F, though > the radio encoding may then require its own M4 or dsp. > > -JimC
A few comments/questions, I tend to agree that a fixed pt implementation may not needed for a single chip solution now that chips like the Cortex M4F are starting to take hold. One question is how much code/table/ram space is needed? A quick gander seems to show some large codebook tables that may be the show stopper. Currently single chip micros are at best 1 or 2Mbytes of flash and even less ram. Having played around with the M4F I think processing power is probably not an issue if one does a little optimizing. I've ported the CuteSDR receiver code to an STM32F4 running 168MHz and it uses <50% cpu including the LWIP network stack and a full duplex implementation of the Speex codec. Maybe apples and oranges but does show a lot of promise for doing DSP on simple uC. Key optimizations are to use the single precision float math versions (cosf vs cos ) etc. May not make a big difference on a big x86 but is essential for processors with single precision FPUs. Other functions where full precision is not needed can further be optimized using some fast versions such as http://code.google.com/p/fastapprox/ ARM also provides a free arm optimised DSP source code library( CMSIS ) for basic dsp operations such as FFT,FIRs etc. If the memory management stuff(malloc etc.) can be MACRO'd so can be replaced and the core codec2 code is not intertwined with other big OS library calls then there may be a chance for a single chip implementation. A low power(as in DC power) part is essential for codec2 to be used in portable battery applications. Just the ramblings from a Neanderthal HW guy who runs away from any processor/OS with a memory management unit. :) Moe, ae4jy ------------------------------------------------------------------------------ LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial Remotely access PCs and mobile devices and provide instant support Improve your efficiency, and focus on delivering more value-add services Discover what IT Professionals Know. Rescue delivers http://p.sf.net/sfu/logmein_12329d2d _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
