[Tremor] Ogg Vorbis on AVR -> try NEC's V850E/ME2 instead!

[Jens Eltze]

Hi Everybody:


Have you ever tried NEC's V850E/ME2? I ported Ogg to the device, it works
flawless. I built my own little unit that can do MP3 and OGG in realtime,
with all rates supported. The nice thing on the ME2 is that the code is
fairly small (due to 16-bit encoding of instructions), and that it supports
external SDRAM. On my board I run the device with 132 MHz, which is an
overkill, but I want to port later other codecs as well. For my system, I
use a DMA controller to do the I/O, and I build a small Compact Flash
interface with standard FAT16 support to get my compressed audio in. There
are other devices from NEC available with enough performance to do the
decoding (same CPU core) and embedded Flash, but you need to check their web
page to see what is available right now.

Regards,

Jens


----- Original Message ----- 
From: "James Dabbs" <jdabbs at tga.com>
To: <tremor at xiph.org>
Sent: Sunday, October 10, 2004 6:44 PM
Subject: RE: [Tremor] Ogg Vorbis on AVR


> > AVR's are high performance 8 bit microcontrollers. They execute most
> > instructions in a single cycle (up to ~20MHz)  They have up to 128k
> > program memory (flash) and can address up to 64K RAM. It does not seem
>
> > to have a HW multiplication instruction. This is probably the fastest
> of
> > all microcontrollers, but it is still a microcontroller.
>
> The AVR is about 5 times to slow to decode Ogg in real time.  You are
> going to need to decode the data into a big memory buffer (SD Flash,
> etc.) and then play it back.  (Since it has no DMA, just moving the
> audio samples out of serial flash to an A/D at 44KHz is going to use up
> a lot of CPU bandwidth.)
>
> If real-time is important, I would look at an a Phillips LPC2106.  It's
> close to the AVR's in size and cost, and its ARM7 core should be able to
> keep up for most applications.
>
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