ModuleWare Reference Guide - Hornad

Arithmetic PartsAbsolute Value (absval)Absolute Value (absval)This part takes the absolute value of the input port din and places the resultin the output port dout. din is assumed to be a signed number in 2’scomplement format.This part is equivalent to n of 2-bit multiplexers, n inverters and an n-bitwide incrementer; where n is the width of the ports.Functiondout= din= (NOT(din)) + 1if the MSB of the input port din = 0OtherwiseTruth TableA 3-bit example:Table 6-3. Absolute Value Truth Tabledin Value of din dout Value of dout000 0 000 0001 1 001 1010 2 010 2011 3 011 3100 -4 100 4101 -3 011 3110 -2 010 2111 -1 001 1ParametersTable 6-4. Absolute Value ParametersParameter Values Defaultdin, dout Port widths (must be > 1) Automaticdout_type ActiveHigh, ActiveLow ActiveHighDesign Rule Checks• An error is issued if the width of any port cannot be determined.• A warning is issued and HDL generation fails for this part if any of the ports are notconnected.102ModuleWare Reference Manual, Library Version 1.9September 18, 2008