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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 logic fetch_nop,
fetch_abort,
input ptr fetch_insn_pc,
fetch_head,
input insn_decode fetch_dec,
output word insn,
output ptr insn_pc,
output insn_decode dec,
output logic abort
);
logic execute, conditional, undefined, nop;
insn_decode hold_dec;
//FIXME: User mode puede hacer msr o mcr y saltare cualquier límite de seguridad
always_comb begin
dec = hold_dec;
dec.ctrl.nop = nop;
dec.ctrl.execute = !flush && dec.ctrl.execute && execute && !nop && !abort;
dec.ctrl.undefined = !flush && (dec.ctrl.undefined || undefined);
dec.ctrl.conditional = !flush && (dec.ctrl.conditional || conditional);
end
core_porch_conds conds
(
.*
);
always_ff @(posedge clk or negedge rst_n)
if(!rst_n) begin
nop <= 0; // Even though it is a NOP
insn <= `NOP;
abort <= 0;
insn_pc <= 0;
hold_dec <= {$bits(hold_dec){1'b0}};
end else if(flush || !stall) begin
nop <= flush ? 1 : fetch_nop;
insn <= flush ? `NOP : fetch_insn;
abort <= flush ? 0 : fetch_abort;
insn_pc <= flush ? fetch_head : fetch_insn_pc;
hold_dec <= fetch_dec;
end
endmodule
|
