ModuleWare Reference Guide - Hornad

Arithmetic PartsVariable Shifter (varshift)Functiondoutdout= din > shiftif mode = logical, 0 is placed in the MSBif mode = arithmetic, the MSB is retainedif mode = circular, LSB of din is placed in the MSBTruth TableA 4-bit input example (mode = logical):A 4-bit input example (mode = arithmetic):if shift > 0if shift < 0dout = din if shift = 0Table 6-52. Variable Shifter Truth Table — 4-bit Input, Mode = Logicaldin shift dout1101 000 (0) 11011101 001 (1) 10101101 010 (2) 01001101 011 (3) 10001101 100 (-4) 00001101 101 (-3) 00011101 110 (-2) 00111101 111 (-1) 0110Table 6-53. Variable Shifter Truth Table — 4-bit Input, Mode = Arithmeticdin shift dout1101 000 (0) 11011101 001 (1) 10101101 010 (2) 01001101 011 (3) 10001101 100 (-4) 11111101 101 (-3) 11111101 110 (-2) 11111101 111 (-1) 1110ModuleWare Reference Manual, Library Version 1.9 137September 18, 2008