[sdiy] Microchip DSP kit $60 > AVR32

Scott Gravenhorst music.maker at gte.net
Fri Mar 21 20:02:36 CET 2008


Eric Brombaugh <ebrombaugh at earthlink.net> wrote:
>Scott Gravenhorst wrote:
>
>>>> It has 4 stereo ins and four stereo
>>>> outs, and optical digital in/out if you want it.
>>> Is that last one for MIDI?
>> 
>> Ack!  How could I miss that?
>> 
>> Thanks Mr. Tellason, I hereby "un-poo".  
>> 
>> A digital in would do nicely, especially if the board has something that does the UART
>> thing in hardware or if the MPU/CPU/MCU has a built in general 
>purpose UART. I don't like > to use a processor to do the serial 
>bit shift thing, I prefer a real UART so that the > CPU/MPU/MCU 
>isn't burdened with that. 
>
>As mentioned earlier, the optical capabilities of the Soundbite board 
>don't include MIDI. The DSP56371 processor on the Soundbite doesn't have 
>a UART either, so you'd either have to use an external processor to 
>handle the MIDI interface and send the results in via SPI, or you'd need 
>to bit-bang the UART function (Ugh!).
>
>Available peripherals on the processor are:
>
>— 2x Enhanced Serial Audio Interface (ESAI): up to 4 receivers and up to 
>6 transmitters (per each), master or slave. I2S, Left justified, Right 
>justified, Sony, AC97, network and other programmable protocols.
>— Serial Host Interface (SHI): SPI and I2C protocols, multi master 
>capability in I2C mode, 10-word receive FIFO, support for 8, 16 and 
>24-bit words.
>— Triple Timer module (TEC).
>— 11 dedicated GPIO pins
>— Digital Audio Transmitter (DAX): 1 serial transmitter capable of 
>supporting the SPDIF, IEC958, CP-340 and AES/EBU digital audio formats.
>— Pins of unused peripherals (except SHI) may be programmed as GPIO lines.
>
>The low GPIO count and Serial Host Interface should be a clue that the 
>intended purpose for this part was as a simple stand-along DSP, or as a 
>peripheral to another processor which sends it commands via the SHI. If 
>I were doing MIDI with this, that's where I'd start.

Ah, ok, I get it now, and thank you.  Given that, for me, I'm better off working with my
Spartan-3E.  If this board had a built in UART of some kind, I'd be tempted just to the DSP
hardware/software, but without ready made MIDI, it's too much trouble (for me).

-- ScottG

-----------------------------------------------------------------

-- Scott Gravenhorst
-- GateMan-III - FPGA Based Monophonic MIDI Synthesizer with SVF
-- PolyDaWG/8 - FPGA Based 8 Voice Polyphonic MIDI Synthesizer
-- phLUTe - FPGA Based Monophonic Physical Model MIDI Synthesizer
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-- NonFatMan: home1.gte.net/res0658s/electronics/
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