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-rw-r--r--rtl/core/porch/porch.sv53
1 files changed, 53 insertions, 0 deletions
diff --git a/rtl/core/porch/porch.sv b/rtl/core/porch/porch.sv
new file mode 100644
index 0000000..6f5caf7
--- /dev/null
+++ b/rtl/core/porch/porch.sv
@@ -0,0 +1,53 @@
+`include "core/uarch.sv"
+
+module core_porch
+(
+ input logic clk,
+ 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 @(posedge clk)
+ if(!stall) begin
+ insn <= fetch_insn;
+ hold_dec <= fetch_dec;
+
+ if(!flush)
+ insn_pc <= fetch_insn_pc;
+ end
+
+ initial begin
+ insn = `NOP;
+ insn_pc = 0;
+ hold_dec = nop;
+ end
+
+endmodule