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module nqcpu (
input clk,
input needWait_i,
output [15:0] addr_o,
output re_o, we_o,
inout [15:0] data_io,
output [15:0] debugPC,
output [9:0] dbg_state,
output [32:0] debugCtrl,
output [15:0] dbg_r0,
output [15:0] dbg_r1,
output [15:0] dbg_r2,
output [15:0] dbg_r3,
output [15:0] dbg_r4,
output [15:0] dbg_r5,
output [15:0] dbg_r6,
output [15:0] dbg_r7,
output dbg_setPC,
output [15:0] dbg_setPCValue,
output [1:0] dbg_statusreg
);
//-- handle data line tristate --
wire [15:0] data_i;
wire [15:0] data_o;
assign data_i = we_o ? 16'h0 : data_io;
assign data_io = we_o ? data_o : 16'hZZZZ;
//-------------------------------
reg [15:0] pc;
initial begin
pc = 16'h0;
end
wire fetch_en, decode_en, alu_en, incr_pc, setPC;
wire [15:0] setPCValue;
wire fetch_re;
wire [15:0] fetched_instr;
wire [15:0] pc_from_fetch;
wire [15:0] fetch_addr;
fetch_stage fetch_inst (
.clk(clk),
.en(fetch_en),
.addr_in(pc),
.mem_re(fetch_re),
.mem_addr(fetch_addr),
.mem_data(data_i),
.instr_out(fetched_instr),
.pc_out(pc_from_fetch)
);
assign re_o = fetch_re;
assign we_o = 1'b0;
assign addr_o = fetch_addr;
always @(posedge clk) begin
if(incr_pc) begin
pc <= pc + 16'h2;
end
else if (setPC & alu_en) begin
pc <= setPCValue;
end
end
wire [32:0] ctrl_from_decoder;
wire [15:0] imm_from_decoder;
wire [15:0] pc_from_decoder;
decoder_stage decoder_inst (
.clk(clk),
.en(decode_en),
.instr_in(fetched_instr),
.pc_in(pc_from_fetch),
.control_signals_out(ctrl_from_decoder),
.imm_out(imm_from_decoder),
.pc_out(pc_from_decoder)
);
wire [2:0] rf_regA;
wire [2:0] rf_regB;
wire [2:0] rf_regDest;
wire [15:0] rf_dataIn;
wire rf_we;
wire rf_hb;
wire rf_lb;
wire [15:0] rf_dataA;
wire [15:0] rf_dataB;
regFile regFile_inst (
.clk(clk),
.regA(rf_regA),
.regB(rf_regB),
.regDest(rf_regDest),
.dataIn(rf_dataIn),
.we(rf_we),
.hb(rf_hb),
.lb(rf_lb),
.dataA(rf_dataA),
.dataB(rf_dataB),
.dbg_r0(dbg_r0),
.dbg_r1(dbg_r1),
.dbg_r2(dbg_r2),
.dbg_r3(dbg_r3),
.dbg_r4(dbg_r4),
.dbg_r5(dbg_r5),
.dbg_r6(dbg_r6),
.dbg_r7(dbg_r7)
);
wire [32:0] ctrl_from_alu;
wire [15:0] imm_from_alu;
wire [15:0] pc_from_alu;
alu_stage alu_inst (
.clk(clk),
.en(alu_en),
.pc_in(pc_from_decoder),
.control_signals_in(ctrl_from_decoder),
.imm_in(imm_from_decoder),
// register file
.rf_regA(rf_regA),
.rf_regB(rf_regB),
.rf_regDest(rf_regDest),
.rf_dataIn(rf_dataIn),
.rf_we(rf_we),
.rf_hb(rf_hb),
.rf_lb(rf_lb),
.rf_dataA(rf_dataA),
.rf_dataB(rf_dataB),
// memory interface
.memData_in(16'hDEAD), // read in from memory
//.memData_out(??), // to write out to memory
.setPC(setPC),
.setPCValue(setPCValue),
.control_signals_out(ctrl_from_alu),
.imm_out(imm_from_alu),
.pc_out(pc_from_alu),
.dbg_statusreg(dbg_statusreg)
);
control_unit control_unit_inst (
.clk(clk),
.needWait(needWait_i),
.fetch_en(fetch_en),
.decode_en(decode_en),
.alu_en(alu_en),
.incr_pc(incr_pc),
.dbg_state(dbg_state)
);
assign debugCtrl = ctrl_from_decoder;
assign debugPC = pc;
assign dbg_setPC = setPC;
assign dbg_setPCValue = setPCValue;
endmodule
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