added minimalistic xilinx sim models

diff --git a/techlibs/xilinx/cells_sim.v b/techlibs/xilinx/cells_sim.v
new file mode 100644 (file)
index 0000000..849ea56
--- /dev/null
+++ b/techlibs/xilinx/cells_sim.v
@@ -0,0 +1,150 @@
+
+module IBUF(O, I);
+output O;
+input  I;
+assign O = I;
+endmodule
+
+module OBUF(O, I);
+output O;
+input  I;
+assign O = I;
+endmodule
+
+module BUFGP(O, I);
+output O;
+input  I;
+assign O = I;
+endmodule
+
+module OBUFT(O, I, T);
+output O;
+input  I, T;
+assign O = T ? 1'bz : I;
+endmodule
+
+module GND(G);
+output G;
+assign G = 0;
+endmodule
+
+module INV(O, I);
+input I;
+output O;
+assign O = !I;
+endmodule
+
+module LUT1(O, I0);
+parameter [1:0] INIT = 0;
+input I0;
+output O;
+assign O = I0 ? INIT[1] : INIT[0];
+endmodule
+
+module LUT2(O, I0, I1);
+parameter [3:0] INIT = 0;
+input I0, I1;
+output O;
+wire [ 1: 0] s1 = I1 ? INIT[ 3: 2] : INIT[ 1: 0];
+assign O = I0 ? s1[1] : s1[0];
+endmodule
+
+module LUT3(O, I0, I1, I2);
+parameter [7:0] INIT = 0;
+input I0, I1, I2;
+output O;
+wire [ 3: 0] s2 = I2 ? INIT[ 7: 4] : INIT[ 3: 0];
+wire [ 1: 0] s1 = I1 ?   s2[ 3: 2] :   s2[ 1: 0];
+assign O = I0 ? s1[1] : s1[0];
+endmodule
+
+module LUT4(O, I0, I1, I2, I3);
+parameter [15:0] INIT = 0;
+input I0, I1, I2, I3;
+output O;
+wire [ 7: 0] s3 = I3 ? INIT[15: 8] : INIT[ 7: 0];
+wire [ 3: 0] s2 = I2 ?   s3[ 7: 4] :   s3[ 3: 0];
+wire [ 1: 0] s1 = I1 ?   s2[ 3: 2] :   s2[ 1: 0];
+assign O = I0 ? s1[1] : s1[0];
+endmodule
+
+module LUT5(O, I0, I1, I2, I3, I4);
+parameter [31:0] INIT = 0;
+input I0, I1, I2, I3, I4;
+output O;
+wire [15: 0] s4 = I4 ? INIT[31:16] : INIT[15: 0];
+wire [ 7: 0] s3 = I3 ?   s4[15: 8] :   s4[ 7: 0];
+wire [ 3: 0] s2 = I2 ?   s3[ 7: 4] :   s3[ 3: 0];
+wire [ 1: 0] s1 = I1 ?   s2[ 3: 2] :   s2[ 1: 0];
+assign O = I0 ? s1[1] : s1[0];
+endmodule
+
+module LUT6(O, I0, I1, I2, I3, I4, I5);
+parameter [63:0] INIT = 0;
+input I0, I1, I2, I3, I4, I5;
+output O;
+wire [31: 0] s5 = I5 ? INIT[63:32] : INIT[31: 0];
+wire [15: 0] s4 = I4 ?   s5[31:16] :   s5[15: 0];
+wire [ 7: 0] s3 = I3 ?   s4[15: 8] :   s4[ 7: 0];
+wire [ 3: 0] s2 = I2 ?   s3[ 7: 4] :   s3[ 3: 0];
+wire [ 1: 0] s1 = I1 ?   s2[ 3: 2] :   s2[ 1: 0];
+assign O = I0 ? s1[1] : s1[0];
+endmodule
+
+module MUXCY(O, CI, DI, S);
+input CI, DI, S;
+output O;
+assign O = S ? CI : DI;
+endmodule
+
+module MUXF7(O, I0, I1, S);
+input I0, I1, S;
+output O;
+assign O = S ? I1 : I0;
+endmodule
+
+module MUXF8(O, I0, I1, S);
+input I0, I1, S;
+output O;
+assign O = S ? I1 : I0;
+endmodule
+
+module VCC(P);
+output P;
+assign P = 1;
+endmodule
+
+module XORCY(O, CI, LI);
+input CI, LI;
+output O;
+assign O = CI ^ LI;
+endmodule
+
+module CARRY4(CO, O, CI, CYINIT, DI, S);
+output [3:0] CO, O;
+input  CI, CYINIT;
+input  [3:0] DI, S;
+wire ci_or_cyinit;
+assign O = S ^ {CO[2:0], ci_or_cyinit};
+assign CO[0] = S[0] ? ci_or_cyinit : DI[0];
+assign CO[1] = S[1] ? CO[0] : DI[1];
+assign CO[2] = S[2] ? CO[1] : DI[2];
+assign CO[3] = S[3] ? CO[2] : DI[3];
+assign ci_or_cyinit = CI | CYINIT;
+endmodule
+
+/*
+module FDRE (Q, C, CR, D, R);
+parameter [0:0] INIT = 1'b0,
+parameter [0:0] IS_C_INVERTED = 1'b0,
+parameter [0:0] IS_D_INVERTED = 1'b0,
+parameter [0:0] IS_R_INVERTED = 1'b0
+output Q;
+input C;
+input CE;
+input D;
+input R;
+// -- FIXME --
+endmodule
+*/
+