DSP BLOCK FOR IMPLEMENTING LARGE MULTIPLIER ON A PROGRAMMABLE INTEGRATED CIRCUIT DEVICE

A programmable integrated circuit device includes a plurality of specialized processing blocks. Each specialized processing block may be small enough to occupy a single row of logic blocks. The specialized processing blocks may be located adjacent one another in different logic block rows, forming a column of adjacent specialized processing blocks. Each specialized processing block includes one or more multipliers based on carry-save adders whose outputs are combined using compressors. Chain-in and chain-out connections to the compressors allow adjacent specialized processing blocks to be cascaded to form arbitrarily large multipliers. Each specialized processing block also includes a carry-propagate adder, and the carry-propagate added in the final specialized processing block of the chain provides the final result. The size of the multiplication that may be performed is limited only by the number of specialized processing blocks in the programmable integrated circuit device.