ModuleWare Reference Guide - Hornad

Multiplier (mult)Arithmetic PartsMultiplier (mult)The multiplier part inputs data bus ports din0 and din1 and places theresult in the output port prod.The multiplication can be performed in two modes: unsigned and signedcontrolled by the value of the enumerated parameter sign_type (Unsigned,Signed).If the width of the output port prod is greater than the sum of the widths ofthe input ports, 0 is padded in the result.If the width of the output port is less than the sum of the widths of the inputports, the most significant bits from the result are ignored.This part is equivalent to an m*n-bit multiplier where m and n are the widths of the ports din0and din1. The implementation of the multiplier is controlled via the synthesis script. Thehardware performance depends on the width of the output port prod. This is a very large partand it is difficult to estimate the hardware performance. This part significantly effects the placeand route of a design.Functionprod= din0 * din1The multiplication is unsigned or signed, depending on the value of the parameter sign_type.Truth TableA 3-bit input, 6-bit output example (sign_type = unsigned):Table 6-34. Multiplier Truth Table — 3-bit Input, 6-bit Output, Unsigneddin0 din1 prod001 011 000011 (3)100 011 001100 (12)011 011 001001 (9)111 011 010101 (21)001 101 000101 (5)100 101 010100 (20)011 101 001111 (15)111 101 100011 (35)ModuleWare Reference Manual, Library Version 1.9 125September 18, 2008