44 lines
1.4 KiB
Systemverilog
44 lines
1.4 KiB
Systemverilog
`ifndef ALU_H_SV
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`define ALU_H_SV
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`include "asu.sv"
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`include "lu.sv"
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// flags[0:0] = Cout
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// flags[1:1] = Overflow
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// flags[2:2] = Zero
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module alu #(parameter width=2)(input logic [3:0] op,
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input logic [2**width-1:0] A, input logic [2**width-1:0] B,
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output logic [2**width-1:0] OUT_1, output logic[2:0] flags
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);
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// intermediate logic for handling asu output
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logic [0:0] asu_op;
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logic [2**width-1:0] asu_out;
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logic [2:0] asu_flags;
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assign asu_op = op[1];
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asu #(width) adder_unit(asu_op, A, B, asu_out, asu_flags[0], asu_flags[1]);
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logic [2**width-1:0] lu_out;
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lu #(width) logic_unit(op[1:0], A, B, lu_out);
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always_comb begin
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case (op)
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4'b0000: begin OUT_1 = asu_out; end
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4'b0001: begin OUT_1 = asu_out; end
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4'b0010: begin OUT_1 = asu_out; end
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4'b0011: begin OUT_1 = asu_out; end
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4'b0100: begin OUT_1 = lu_out; end
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4'b0101: begin OUT_1 = lu_out; end
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4'b0110: begin OUT_1 = lu_out; end
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4'b0111: begin OUT_1 = lu_out; end
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4'b1010: begin OUT_1 = (asu_out[2**width-1] ^ asu_flags[1]) & {{(width-1){1'b0}}, 1'b1}; end
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4'b1011: begin OUT_1 = ~asu_flags[0] & {{(width-1){1'b0}}, 1'b1}; end
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default: begin OUT_1 = {(2**width){1'b0}}; end
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endcase
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asu_flags[2] = OUT_1 == 0;
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flags = asu_flags;
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end
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endmodule
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`endif
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