ModuleWare Reference Guide - Hornad

Arithmetic PartsVariable Shifter (varshift)A 4-bit input example (mode = circular):Table 6-54. Variable Shifter Truth Table — 4-bit Input, Mode = Circulardin shift dout1101 000 (0) 11011101 001 (1) 10111101 010 (2) 01111101 011 (3) 11101101 100 (-4) 11011101 101 (-3) 10111101 110 (-2) 01111101 111 (-1) 1110ParametersTable 6-55. Variable Shifter ParametersParameter Values Defaultdin, doutshiftPort width (must be > 1)Port width (must be > 0)AutomaticAutomaticmode Logical, Arithmetic, Circular LogicalDesign 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.• A warning is issued but the generation succeeds if the shift value is greater than the din portsize in the circular mode.138ModuleWare Reference Manual, Library Version 1.9September 18, 2008