[sdiy] Function Generator ICs

[ASSI]

On Freitag 21 September 2007, David Betz wrote:
> The only use I make of "gate counts" is to compare two FPGA chips in
> the same family. I'm assuming that a Xilinx Spartan 3 that claims
> "1000k gates" will hold five times as much logic as one that claims
> "200k gates". Is that a safe assumption?

Sort of.  It is still better to look at the individual CLB, IOB, RAM, 
multiplier and DCM resources than the compound "system gates" figure 
that munges everything into a single marketing number.  So for your 
example, the breakdown is:

Device   Gates   CLB BRAM MULT DCM IOB
XC3S200   200K   480 216K   12   4 173
XC3S1000 1000K 1,920 432K   24   4 391
XC3S2000 2000K 5,120 720K   40   4 565

So coming from the 3S200 you get four times the CLB, 2 times the RAM and 
2 times the multipliers with the 3S1000 and never five times of 
anything.  However if you look at the 3S2000 you get more than ten 
times the CLB and 3 1/3 times the RAM and multipliers.


Achim.
-- 
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk]>+

Waldorf MIDI Implementation & additional documentation:
http://Synth.Stromeko.net/Downloads.html#WaldorfDocs