[sdiy] ARM vs dsPIC performance

[Seb Francis]

Robin Whittle wrote:
> I don't know how fancy the addressing modes are, with auto increments
> etc.  In the ET-ARM Stamp, the chip runs at 58.9824MHz, so I guess a
> multiply-accumulate takes about 100ns.
>
>   
<snip>
> Without doing a lot of research, it is my impression that a 40 MIPs
> dsPIC, programmed in assembler, would be faster than this 60 MHz ARM
> chip, for general 16 bit DSP operations.
>
>   

Yeah with a dsPIC running at 40MIPS a multiply and accumulate takes 
25ns, and included in this time it can optionally prefetch the operands 
for the next MAC, increment the operand pointers, and even store back 
the result from the opposite accumulator.  It also supports circular 
buffers in hardware, so no need to check and reset the operand pointer(s).

And as Robin said you can get dsPICs with a proper CODEC interface that 
will allow you to do 2-channel I2S or 12-channel AC97 completely in 
hardware.

Seb