Lpc2000

At 05:24 PM 1/28/05 +0000, you wrote:
>In looking at the SSP specification for the LPC2138, it can handle a
>maximum frame size of 16 bits.  Does anyone know of a way to extend
>this to 24bits without CPU intervention? Has anyone done something
>similar?  The ADS2171 will have a 100kHz data rate, so I'm worried
>about having interrupts on a Byte by Byte basis, as that would be a
>300kHz interrupt rate (100kHz X 24/8).


I haven't worked with it yet, but it looks as if the FIFO should reduce 
your rate a little more, conservatively 4x (8 frame FIFO, 8 bit frames, 
interrupt on 1/2 full FIFO, FIFO emptied  before another entry arrives) 
which take you down to 75kHz.  That still only gives you 13 microseconds to 
perform the interrupt though (assuming you do nothing else).

Robert

" 'Freedom' has no meaning of itself.  There are always restrictions,
be they legal, genetic, or physical.  If you don't believe me, try to
chew a radio signal. "

                         Kelvin Throop, III