[sdiy] 32 bit RISC MIPS32 PICs in 28 pin DIP with audio codec interfaces & USB

[dan snazelle]

On Mar 4, 2012, at 10:20 PM, Robin Whittle wrote:

> From: Re: [sdiy] DECISION TIME: need a Ucontroller/ARM/DSP chip that
>          will process audio
> Hi Jay,
> 
> Thanks for pointing this out:
> 
>> These will be coming out in the next few weeks:
>> http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en557433
>> http://www.microchipdirect.com/ProductSearch.aspx?Keywords=PIC32MX250F128D
> 
> For instance, the 28 pin DIP PIC32MX150F128B (or D with 44 pins an TQFP
> and QFN) has an SPI port which is apparently capable of talking
> bidirectionally to a stereo DAC/ADC (AKA audio codec).  I haven't chased
> the details, but page 165 of the datasheet states that it can do the I2S
> protocol which is often used by codecs.  This port has FIFOs.
> 
> This chip of the series has the most program memory (128k bytes) and RAM
> (32k bytes), and a 10 bit ADC.  They are available now for $3.70 in 1 to
> 25 quantities.  I guess there is a 44 pin version development header
> board which could be used to develop for the 28 pin DIP version without
> using any of the 28 pin DIP pins for the debugger connection.
> 
> The PIC32MX250F128x is similar, but has USB capabilities which I have
> not looked at.
> 
> The CPU is 40MHz with single cycle 16 x 32 multiply and accumulate (MAC)
> two cycle 32 x 32 MAC.  However, this is a RISC CPU so I wonder how long
> it takes to calculate operand addresses and read the operands.  The
> dsPIC CPUs are 16 bit but have this totally wired - they can steam ahead
> doing a 16 bit MAC with all address calculations and reads and writes
> pipelined, one per 40MHz clock cycle.
> 
> There's not enough pins for accessing external RAM in any simple and
> high-speed manner.
> 
> The CPU design is a MIPS32 "M4K", but I think this is "4Km", licensed
> from MIPS:
> 
>  http://www.mips.com/products/cores/32-64-bit-cores/mips32-4k/
> 
> Its amazing what will fit into a 28 pin DIP package.  I haven't looked
> exhaustively, but as far as I know there are no 16 bit audio codecs in
> DIP packages.  For field serviceability, a codec could be mounted in a
> DIP header.
> 
>  - Robin      http://www.firstpr.com.au/rwi/dfish/
> 
> 
> 
i keep hearing about this but what are audio codecs and what is a good one?




thanks









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