// ALU Infrastructure
// --------------------------------------------------------
-module \$__alu_ripple (A, B, CI, X, Y, CO, CS);
+module \$__alu_ripple (A, B, CI, X, Y, CO);
parameter WIDTH = 1;
input [WIDTH-1:0] A, B;
output [WIDTH-1:0] X, Y;
input CI;
- output CO, CS;
+ output [WIDTH-1:0] CO;
wire [WIDTH:0] carry;
assign carry[0] = CI;
- assign CO = carry[WIDTH];
- assign CS = carry[WIDTH-1];
+ assign CO = carry[WIDTH:1];
genvar i;
generate
input [WIDTH-1:0] P, G;
input CI;
- output reg [WIDTH:0] CO;
+ output [WIDTH-1:0] CO;
integer i, j;
reg [WIDTH-1:0] p, g;
end
end
- assign CO = {g, CI};
+ assign CO = g;
endmodule
-module \$__alu_lookahead (A, B, CI, X, Y, CO, CS);
+module \$__alu_lookahead (A, B, CI, X, Y, CO);
parameter WIDTH = 1;
input [WIDTH-1:0] A, B;
output [WIDTH-1:0] X, Y;
input CI;
- output CO, CS;
+ output [WIDTH-1:0] CO;
wire [WIDTH-1:0] P, G;
- wire [WIDTH:0] C;
-
- assign CO = C[WIDTH];
- assign CS = C[WIDTH-1];
+ wire [WIDTH:0] carry;
genvar i;
generate
\$_XOR_ gate2 ( .A(a), .B(b), .Y(p) );
\$_XOR_ gate3 ( .A(p), .B(c), .Y(y) );
- assign a = A[i], b = B[i], c = C[i];
+ assign a = A[i], b = B[i], c = carry[i];
assign P[i] = p, G[i] = g, X[i] = p, Y[i] = y;
end
endgenerate
- \$__lcu #(.WIDTH(WIDTH)) lcu (.P(P), .G(G), .CI(CI), .CO(C));
+ \$__lcu #(.WIDTH(WIDTH)) lcu (.P(P), .G(G), .CI(CI), .CO(CO));
+ assign carry = {CO, CI};
endmodule
-module \$__alu (A, B, CI, BI, X, Y, CO, CS);
+module \$__alu (A, B, CI, BI, X, Y, CO);
parameter A_SIGNED = 0;
parameter B_SIGNED = 0;
parameter A_WIDTH = 1;
// carry in, sub, carry out, carry sign
input CI, BI;
- output CO, CS;
+ output [Y_WIDTH-1:0] CO;
wire [Y_WIDTH-1:0] A_buf, B_buf;
\$pos #(.A_SIGNED(A_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf));
\$pos #(.A_SIGNED(B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf));
`ifdef ALU_RIPPLE
- \$__alu_ripple #(.WIDTH(Y_WIDTH)) _TECHMAP_REPLACE_ (.A(A_buf), .B(BI ? ~B_buf : B_buf), .CI(CI), .X(X), .Y(Y), .CO(CO), .CS(CS));
+ \$__alu_ripple #(.WIDTH(Y_WIDTH)) _TECHMAP_REPLACE_ (.A(A_buf), .B(BI ? ~B_buf : B_buf), .CI(CI), .X(X), .Y(Y), .CO(CO));
`else
if (Y_WIDTH <= 4) begin
- \$__alu_ripple #(.WIDTH(Y_WIDTH)) _TECHMAP_REPLACE_ (.A(A_buf), .B(BI ? ~B_buf : B_buf), .CI(CI), .X(X), .Y(Y), .CO(CO), .CS(CS));
+ \$__alu_ripple #(.WIDTH(Y_WIDTH)) _TECHMAP_REPLACE_ (.A(A_buf), .B(BI ? ~B_buf : B_buf), .CI(CI), .X(X), .Y(Y), .CO(CO));
end else begin
- \$__alu_lookahead #(.WIDTH(Y_WIDTH)) _TECHMAP_REPLACE_ (.A(A_buf), .B(BI ? ~B_buf : B_buf), .CI(CI), .X(X), .Y(Y), .CO(CO), .CS(CS));
+ \$__alu_lookahead #(.WIDTH(Y_WIDTH)) _TECHMAP_REPLACE_ (.A(A_buf), .B(BI ? ~B_buf : B_buf), .CI(CI), .X(X), .Y(Y), .CO(CO));
end
`endif
endmodule
// ALU Cell Types: Compare, Add, Subtract
// --------------------------------------------------------
-`define ALU_COMMONS(_width, _ci, _bi) """
+`define ALU_COMMONS(_width, _sub) """
parameter A_SIGNED = 0;
parameter B_SIGNED = 0;
parameter A_WIDTH = 1;
input [B_WIDTH-1:0] B;
output [Y_WIDTH-1:0] Y;
- wire alu_co, alu_cs;
- wire [WIDTH-1:0] alu_x, alu_y;
+ wire [WIDTH-1:0] alu_x, alu_y, alu_co;
+ wire [WIDTH:0] carry = {alu_co, |_sub};
\$__alu #(
.A_SIGNED(A_SIGNED),
) alu (
.A(A),
.B(B),
- .CI(_ci),
- .BI(_bi),
+ .CI(|_sub),
+ .BI(|_sub),
.X(alu_x),
.Y(alu_y),
- .CO(alu_co),
- .CS(alu_cs)
+ .CO(alu_co)
);
wire cf, of, zf, sf;
- assign cf = !alu_co;
- assign of = alu_co ^ alu_cs;
+ assign cf = !carry[WIDTH];
+ assign of = carry[WIDTH] ^ carry[WIDTH-1];
assign sf = alu_y[WIDTH-1];
"""
module \$lt (A, B, Y);
wire [1023:0] _TECHMAP_DO_ = "RECURSION; opt_const -mux_undef -mux_bool -fine;;;";
- `ALU_COMMONS(`MAX(A_WIDTH, B_WIDTH), 1, 1)
+ `ALU_COMMONS(`MAX(A_WIDTH, B_WIDTH), 1)
assign Y = A_SIGNED && B_SIGNED ? of != sf : cf;
endmodule
module \$le (A, B, Y);
wire [1023:0] _TECHMAP_DO_ = "RECURSION; opt_const -mux_undef -mux_bool -fine;;;";
- `ALU_COMMONS(`MAX(A_WIDTH, B_WIDTH), 1, 1)
+ `ALU_COMMONS(`MAX(A_WIDTH, B_WIDTH), 1)
assign Y = &alu_x || (A_SIGNED && B_SIGNED ? of != sf : cf);
endmodule
module \$add (A, B, Y);
wire [1023:0] _TECHMAP_DO_ = "RECURSION; opt_const -mux_undef -mux_bool -fine;;;";
- `ALU_COMMONS(Y_WIDTH, 0, 0)
+ `ALU_COMMONS(Y_WIDTH, 0)
assign Y = alu_y;
endmodule
module \$sub (A, B, Y);
wire [1023:0] _TECHMAP_DO_ = "RECURSION; opt_const -mux_undef -mux_bool -fine;;;";
- `ALU_COMMONS(Y_WIDTH, 1, 1)
+ `ALU_COMMONS(Y_WIDTH, 1)
assign Y = alu_y;
endmodule