If you do not need parallel speed consider serial multiplication -
google "serial 8 bit multiplier", you will get a lot of approaches.
This verilog module working but is it UDB killer :-)
is possible make this on datapath ?
or question serial 8bit multiplier is equivalent ?
(my idea is two 8bit sine wave multiplied like FM synthesis)
Serial approach feasability depends on your computation rate
requirements. If this is being done at audio rates intuition tells
me serial approach should work fine. This of course would be
a verilog solution.
Thanks info Dana
Im tested this serial multiplier
working but 80% UDB comsumption :-(
DataPath ALU not support multiplification ? Thanks info
No, the ALU doesn't support multiplication. But it supports addition, so you can roll this into your own multiplier (though this will be some work). But it should be possible to do 8x8 bit multiplication within two UDBs (which get joined to allow 16-bit-logic)
Thanks info Hli
Is possible make example ?
Many many thanks
Unfortunately I currently don't have time for that. But since you already have a verilog solution using an adder made out of PLDs, you can use that as a starting point. The working principle is the same, but you use the ALU for the addition and for storage.
The algorithm is straightforward:
if lowest bit of multiplicant = 1 Add multiplicator to Acc
shift multiplicator Left by one
shift multiplicant right by one
if multiplicant = 0 we are ready, Acc contains the 16 bit result, else go back to the "if" stasement above
Happy verilog / datapath coding