WIP: failed attempt to use many-input or gates

Gate level implementation for the following components:
- ALU
- MUX32_16x1

TESTBENCH/barrel_shifter_tb.v

@@ -18,7 +18,7 @@ reg LnR;
 wire [31:0] Y;
 
 integer reg_idx;
-reg [`DATA_INDEX_LIMIT:0] result[0:63];
+reg [`DATA_INDEX_LIMIT:0] result[0:123];
 
 integer i, e;
 integer no_of_test=0;
@@ -33,7 +33,7 @@ D=32'ha5a5a5a5;
 S=32'h00000000;
 LnR=1'b1; // left shift
 
-for(i=1; i<33; i=i+1)
+for(i=1; i<63; i=i+1)
 begin
 #5 
 no_of_test = no_of_test + 1;
@@ -51,7 +51,7 @@ end
 
 #5 LnR=1'b0; // right shift
 
-for(i=1; i<33; i=i+1)
+for(i=1; i<63; i=i+1)
 begin
 #5 
 no_of_test = no_of_test + 1;

alu.v

@@ -31,7 +31,51 @@ input [`ALU_OPRN_INDEX_LIMIT:0] OPRN; // operation code
 output [`DATA_INDEX_LIMIT:0] OUT; // result of the operation.
 output ZERO;
 
-// TBD
+wire [31:0] //res,
+            res_addsub, res_slt,
+            res_shift,
+            res_mul,
+            res_and, res_or, res_nor;
+wire [31:0] res;
 
+// add = xx0001
+// sub = xx0010
+// slt = xx1001
+//         ^ ^ these bits
+// can use oprn[1] or oprn[3] for SnA
+wire SnA;
+or (SnA, OPRN[1], OPRN[3]);
+RC_ADD_SUB_32 addsub(.Y(res_addsub), .A(OP1), .B(OP2), .SnA(SnA));
+buf slt [31:0] (res_slt, {31'b0,res_addsub[31]});
+
+// shift_r = xx0100
+// shift_l = xx0101
+//                ^ this bit
+// can use oprn[0] for LnR
+SHIFT32 shift(res_shift, OP1, OP2, OPRN[0]);
+
+// mul = xx0011
+MULT32 mul(.LO(res_mul), .A(OP1), .B(OP2));
+
+// and = xx0110
+// or  = xx0111
+// nor = xx1000
+AND32_2x1 and32(res_and, OP1, OP2);
+OR32_2x1 or32(res_or, OP1, OP2);
+NOR32_2x1 nor32(res_nor, OP1, OP2);
+
+MUX32_16x1 out(.Y(res), .S(OPRN[3:0]),
+               .I1(res_addsub), .I2(res_addsub), .I3(res_mul),
+               .I4(res_shift),.I5(res_shift),
+               .I6(res_and), .I7(res_or), .I8(res_nor),
+               .I9(res_slt)
+);
+
+// or bits of result for zero flag
+wire nzf;
+or (nzf, res[24:0]);
+
+not (ZERO, nzf);
+buf res_out [31:0] (OUT, res);
 
 endmodule

barrel_shifter.v

@@ -22,20 +22,14 @@ input [31:0] S;
 input LnR;
 
 // check if upper bits are nonzero
-wire oob [31:5];
+wire oob;
-buf (oob[5], S[5]);
+or (oob, S[31:5]);
-genvar i;
-generate
-    for (i = 6; i < 32; i = i + 1) begin : shift_oob_gen
-        or (oob[i], oob[i-1], S[i]);
-    end
-endgenerate
 
 wire [31:0] shifted;
 BARREL_SHIFTER32 shifter(shifted, D, S[4:0], LnR);
 
 // return 0 if S >= 32
-MUX32_2x1 mux_oob(Y, shifted, 32'b0, oob[31]);
+MUX32_2x1 mux_oob(Y, shifted, 32'b0, oob);
 
 endmodule
 

logic.v

@@ -141,6 +141,12 @@ output [3:0] D;
 // input
 input [1:0] I;
 
-// TBD
+wire I_not [1:0];
+not I_inv[1:0] (I_not, I);
+
+and (D[0], I_not[1], I_not[0]);
+and (D[1], I_not[1], I[0]);
+and (D[2], I[1], I_not[0]);
+and (D[3], I[1], I[0]);
 
 endmodule

mux.v

@@ -55,7 +55,11 @@ input [31:0] I14;
 input [31:0] I15;
 input [3:0] S;
 
-// TBD
+
+wire [31:0] x0, x1;
+MUX32_8x1 mux8_0(x0, I0, I1, I2, I3, I4, I5, I6, I7, S[2:0]);
+MUX32_8x1 mux8_1(x1, I8, I9, I10, I11, I12, I13, I14, I15, S[2:0]);
+MUX32_2x1 out(Y, x0, x1, S[3]);
 
 endmodule
 
@@ -74,7 +78,10 @@ input [31:0] I6;
 input [31:0] I7;
 input [2:0] S;
 
-// TBD
+wire [31:0] x0, x1;
+MUX32_4x1 mux4_0(x0, I0, I1, I2, I3, S[1:0]);
+MUX32_4x1 mux4_1(x1, I4, I5, I6, I7, S[1:0]);
+MUX32_2x1 out(Y, x0, x1, S[2]);
 
 endmodule
 
@@ -89,7 +96,10 @@ input [31:0] I2;
 input [31:0] I3;
 input [1:0] S;
 
-// TBD
+wire [31:0] x0, x1;
+MUX32_2x1 mux2_0(x0, I0, I1, S[0]);
+MUX32_2x1 mux2_1(x1, I2, I3, S[0]);
+MUX32_2x1 out(Y, x0, x1, S[1]);
 
 endmodule
 
@@ -103,17 +113,19 @@ input [31:0] I1;
 input S;
 
 // only need 1 not gate
+wire S_not;
 not (S_not, S);
 
-wire [31:0] x0, x1;
+// wire [31:0] x0, x1;
 
 genvar i;
 generate
     for (i = 0; i < 32; i = i + 1)
     begin : mux32_gen_loop
-        and (x0[i], S_not, I0[i]);
+        wire x0, x1;
-        and (x1[i], S, I1[i]);
+        and (x0, S_not, I0[i]);
-        or (Y[i], x0[i], x1[i]);
+        and (x1, S, I1[i]);
+        or (Y[i], x0, x1);
     end
 endgenerate
 
@@ -126,6 +138,7 @@ output Y;
 //input list
 input I0, I1, S;
 
+wire S_not, x0, x1;
 not (S_not, S);
 and (x0, S_not, I0);
 and (x1, S, I1);