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`include "core/uarch.sv"
module core_porch
(
input logic clk,
rst_n,
flush,
stall,
input psr_flags flags,
input word fetch_insn,
input ptr fetch_insn_pc,
input insn_decode fetch_dec,
output word insn,
output ptr insn_pc,
output insn_decode dec
);
logic execute, conditional, undefined;
insn_decode nop, hold_dec;
core_porch_conds conds
(
.*
);
assign nop.ctrl.execute = 0;
assign nop.ctrl.undefined = 0;
assign nop.ctrl.conditional = 0;
always_comb begin
dec = hold_dec;
dec.ctrl.execute = !flush && dec.ctrl.execute && execute;
dec.ctrl.undefined = !flush && (dec.ctrl.undefined || undefined);
dec.ctrl.conditional = !flush && (dec.ctrl.conditional || conditional);
end
always_ff @(posedge clk or negedge rst_n)
if(!rst_n) begin
insn <= `NOP;
insn_pc <= 0;
hold_dec <= nop;
end else if(!stall) begin
insn <= fetch_insn;
hold_dec <= fetch_dec;
if(!flush)
insn_pc <= fetch_insn_pc;
end
endmodule
|
