From 601835e33298015cf49f0ab33a7ef3d61b003ad9 Mon Sep 17 00:00:00 2001
From: Alejandro Soto <alejandro@34project.org>
Date: Sat, 24 Sep 2022 21:41:46 -0600
Subject: Implement initial decoder

---
 rtl/core/decode/decode.sv | 65 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 rtl/core/decode/decode.sv

(limited to 'rtl/core/decode/decode.sv')

diff --git a/rtl/core/decode/decode.sv b/rtl/core/decode/decode.sv
new file mode 100644
index 0000000..3470665
--- /dev/null
+++ b/rtl/core/decode/decode.sv
@@ -0,0 +1,65 @@
+`include "core/isa.sv"
+`include "core/psr.sv"
+`include "core/uarch.sv"
+
+module core_decode
+(
+	input  logic[31:0] insn,
+	input  psr_flags   flags,
+	output logic       execute,
+	                   undefined
+);
+
+	logic cond_undefined;
+
+	//TODO
+	logic link;
+	logic[29:0] offset;
+	core_decode_conds conds
+	(
+		.cond(insn `FIELD_COND),
+		.undefined(cond_undefined),
+		.*
+	);
+
+	logic branch_link;
+	logic[29:0] branch_offset;
+
+	core_decode_branch branch
+	(
+		.*
+	);
+
+	//TODO
+	alu_op op;
+	reg_num rn, rd;
+	logic writeback, update_flags, restore_spsr, zero_fst, negate_fst, negate_snd, carry_in;
+	core_decode_data data
+	(
+		.*
+	);
+
+	always_comb begin
+		undefined = cond_undefined;
+
+		priority case(insn `FIELD_OP) inside
+			`GROUP_B: ;
+
+			`GROUP_ALU: begin
+			end
+
+			`INSN_MUL: ;
+			`GROUP_BIGMUL: ;
+			`GROUP_LDST_MISC: ;
+			`GROUP_LDST_MULT: ;
+			`GROUP_SWP: ;
+			`GROUP_CP: ;
+			`INSN_MRS: ;
+			`GROUP_MSR: ;
+			`INSN_SWI: ;
+
+			default: undefined = 1;
+		endcase
+	end
+
+endmodule
-- 
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