My name is Daniel and I am a student at Louisiana State University. I'm presently going through the addaccu tutorial from Alliance and have an error when I simulate the specifications netlist in part 6.2. The following error occurs: Error 109 :signal `cki` never assigned cannot continue further more. Do I have to expand the simulation pattern file (addaccu.pat) and include 'cki' in it? How would I do that? Is not 'cki' the clock? I attached that simulation step as well as the simulation pattern file I'm using. Thanks for any help and suggestions. Daniel Wildhaber addaccu.pat =========================================================================== in vdde ; in vsse ; in vdd; in vss; in a(3 to 0); in b(3 to 0); in sel;; in ck;;; out s(3 to 0); begin # a=0, b=3, sel=direct input, we expect value 3 on s pat_1 : 1 0 1 0 0000 0011 0 0 ?0011 ; # a=1, b=3, sel=direct input, we expect value 4 on s pat_2 : 1 0 1 0 0001 0011 0 0 ?0100 ; # a=7, b=3, sel=direct input, we expect value bin 1010 on s pat_3 : 1 0 1 0 0111 0011 0 0 ?1010 ; # a=7, b=3, sel=direct input, we set ck to 1, we still expect bin 1010 on s pat_4 : 1 0 1 0 0111 0011 0 1 ?1010 ; # when ck falls to 0, the computed value (7+3=bin 1010) is stored in accu pat_5 : 1 0 1 0 0111 0011 0 0 ?1010 ; # if we choose sel=accu output, we expect value bin 1010 + 4= bin 1110 on s # even if a=1111 pat_6 : 1 0 1 0 1111 0100 1 0 ?1110 ; # back to normal mode, 5+4=9 pat_7 : 1 0 1 0 0101 0100 0 0 **** ; end; ========================================================================== asimut addaccu addaccu schema @ @@@@ @ @ @@@@@@@@@@ @ @ @@ @@@ @ @@ @ @@@ @@ @ @ @ @@ @ @@@ @@@ @@@ @@ @@@ @@@ @@@@ @@ @ @@ @@@@ @@@@ @@@ @@ @@ @@ @@ @@ @ @@ @@@@ @@ @@ @@ @@ @@ @@ @@ @ @@ @@@ @@ @@ @@ @@ @@ @@ @@ @@@@@@@ @ @@ @@ @@ @@ @@ @@ @@ @@ @ @@ @@ @@ @@ @@ @@ @@ @@ @@ @@ @ @@ @@@ @ @@ @@ @@ @@ @@ @@@ @@ @@@@ @@@@ @ @@@@ @@@@@@ @@@@ @@@ @@@ @@@@ @@ @@@@@@ A SIMUlation Tool Alliance CAD System 3.0, asimut v1.93 Copyright (c) 1991...1994, MASI, CAO-VLSI Team E-mail support: cao-vlsi@masi.ibp.fr Paris, FRANCE, Europe, Earth, Solar system, Milky Way, ... Initializing ... Searching `addaccu` ... Compiling `addaccu` (Structural) ... Flattening the root figure ... Searching `a2_y` ... BEH : Compiling `a2_y.vbe` (Behaviour) ... Making GEX ... Searching `o3_y` ... BEH : Compiling `o3_y.vbe` (Behaviour) ... Making GEX ... Searching `xr2_y` ... BEH : Compiling `xr2_y.vbe` (Behaviour) ... Making GEX ... Searching `n1_y` ... BEH : Compiling `n1_y.vbe` (Behaviour) ... Making GEX ... Searching `mx2_y` ... BEH : Compiling `mx2_y.vbe` (Behaviour) ... Making GEX ... Searching `ms_y` ... BEH : Compiling `ms_y.vbe` (Behaviour) ... Making GEX ... Searching `pvsse_sp` ... BEH : Compiling `pvsse_sp.vbe` (Behaviour) ... Making GEX ... Searching `pvdde_sp` ... BEH : Compiling `pvdde_sp.vbe` (Behaviour) ... Making GEX ... Searching `pvssi_sp` ... BEH : Compiling `pvssi_sp.vbe` (Behaviour) ... Making GEX ... Searching `pvddi_sp` ... BEH : Compiling `pvddi_sp.vbe` (Behaviour) ... Making GEX ... Searching `po_sp` ... BEH : Compiling `po_sp.vbe` (Behaviour) ... Making GEX ... Searching `pi_sp` ... BEH : Compiling `pi_sp.vbe` (Behaviour) ... Making GEX ... Searching pattern file : `addaccu` ... Restoring ... Error 109 :signal `cki` never assigned cannot continue further more. ==========================================================================