Split regfile read select logic out of control.sv

3 files changed, 56 insertions, 12 deletions

diff --git a/conspiracion.qsf b/conspiracion.qsf
index a75f0df..8702cf6 100644
--- a/conspiracion.qsf
+++ b/conspiracion.qsf
@@ -143,6 +143,7 @@ set_global_assignment -name SYSTEMVERILOG_FILE rtl/core/control/data.sv
 set_global_assignment -name SYSTEMVERILOG_FILE rtl/core/control/exception.sv
 set_global_assignment -name SYSTEMVERILOG_FILE rtl/core/control/issue.sv
 set_global_assignment -name SYSTEMVERILOG_FILE rtl/core/control/ldst/pop.sv
+set_global_assignment -name SYSTEMVERILOG_FILE rtl/core/control/select.sv
 set_global_assignment -name SYSTEMVERILOG_FILE rtl/core/control/stall.sv
 set_global_assignment -name SYSTEMVERILOG_FILE rtl/core/control/writeback.sv
 set_global_assignment -name SYSTEMVERILOG_FILE rtl/core/cp15/cp15.sv
diff --git a/rtl/core/control/control.sv b/rtl/core/control/control.sv
index cc8f160..629e1d9 100644
--- a/rtl/core/control/control.sv
+++ b/rtl/core/control/control.sv
@@ -56,7 +56,7 @@ module core_control
 
 	logic ldst, ldst_pre, ldst_increment, ldst_writeback, pop_valid;
 	word mem_offset;
-	reg_num r_shift, popped_upper, popped_lower, popped;
+	reg_num popped_upper, popped_lower, popped;
 	reg_list mem_regs, next_regs_upper, next_regs_lower;
 
 	assign reg_mode = `MODE_SVC; //TODO
@@ -85,6 +85,11 @@ module core_control
 		.*
 	);
 
+	core_control_select ctrl_select
+	(
+		.*
+	);
+
 	core_control_ldst_pop ctrl_ldst_pop
 	(
 		.regs(mem_regs),
@@ -130,10 +135,6 @@ module core_control
 		unique case(next_cycle)
 			ISSUE:
 				if(issue) begin
-					ra <= dec_data.rn;
-					rb <= dec_snd.r;
-					r_shift <= dec_snd.r_shift;
-
 					// TODO: dec_ldst.unprivileged/user_regs
 					// TODO: byte/halfword sizes
 					ldst <= dec.ldst;
@@ -152,8 +153,7 @@ module core_control
 					mem_write <= !dec_ldst.load;
 				end
 
-			RD_INDIRECT_SHIFT:
-				rb <= r_shift;
+			RD_INDIRECT_SHIFT: ;
 
 			WITH_SHIFT: ;
 
@@ -166,11 +166,6 @@ module core_control
 				if(cycle != TRANSFER || mem_ready) begin
 					mem_regs <= ldst_increment ? next_regs_lower : next_regs_upper;
 					mem_addr <= ldst_pre ? q_alu[31:2] : alu_a[31:2];
-
-					if(pop_valid)
-						rb <= popped;
-					else
-						rb <= final_rd; // Viene de dec_ldst.rd
 				end
 
 				mem_start <= cycle != TRANSFER || (mem_ready && pop_valid);
diff --git a/rtl/core/control/select.sv b/rtl/core/control/select.sv
new file mode 100644
index 0000000..a073e24
--- /dev/null
+++ b/rtl/core/control/select.sv
@@ -0,0 +1,48 @@
+`include "core/uarch.sv"
+
+module core_control_select
+(
+	input  logic       clk,
+
+	input  data_decode dec_data,
+	input  snd_decode  dec_snd,
+
+	input  ctrl_cycle  cycle,
+	                   next_cycle,
+	input  logic       issue,
+	                   mem_ready,
+	                   pop_valid,
+	input  reg_num     popped,
+	                   final_rd,
+
+	output reg_num     ra,
+	                   rb
+);
+
+	reg_num r_shift;
+
+	always_ff @(posedge clk)
+		unique0 case(next_cycle)
+			ISSUE:
+				if(issue) begin
+					ra <= dec_data.rn;
+					rb <= dec_snd.r;
+					r_shift <= dec_snd.r_shift;
+				end
+
+			RD_INDIRECT_SHIFT:
+				rb <= r_shift;
+
+			TRANSFER:
+				if(cycle != TRANSFER || mem_ready)
+					// final_rd viene de dec_ldst.rd
+					rb <= pop_valid ? popped : final_rd;
+		endcase
+
+	initial begin
+		ra = {$bits(ra){1'b0}};
+		rb = {$bits(rb){1'b0}};
+		r_shift = {$bits(r_shift){1'b0}};
+	end
+
+endmodule