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31 lines
914 B
31 lines
914 B
3 years ago
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`timescale 1ns / 1ps
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// 跳转单元
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module BranchUnit #(
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parameter PC_W = 9
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)(
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input logic [PC_W - 1:0] cur_pc,
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input logic [31:0] imm,
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input logic jalr_sel,
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input logic branch_taken, // Branch
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input logic [31:0] alu_result,
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output logic [31:0] pc_plus_imm, // PC + imm
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output logic [31:0] pc_plus_4, // PC + 4
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output logic [31:0] branch_target, // BrPC
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output logic pc_sel
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);
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logic [31:0] pc;
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assign pc = {23'b0, cur_pc};
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always_comb
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begin
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pc_plus_4 = pc + 32'd4;
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pc_plus_imm = pc + imm;
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pc_sel = jalr_sel | (branch_taken & alu_result[0]);
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if (jalr_sel == 1'b1)
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branch_target = alu_result & 32'hfffffffe; // jalr
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else
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branch_target = pc + (imm << 1); // jal and beq
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end
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endmodule
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