verilog/rtl/ibex_core/ibex_counter.v

module ibex_counter (
	clk_i,
	rst_ni,
	counter_inc_i,
	counterh_we_i,
	counter_we_i,
	counter_val_i,
	counter_val_o,
	counter_val_upd_o
);
	parameter signed [31:0] CounterWidth = 32;
	parameter [0:0] ProvideValUpd = 0;
	input wire clk_i;
	input wire rst_ni;
	input wire counter_inc_i;
	input wire counterh_we_i;
	input wire counter_we_i;
	input wire [31:0] counter_val_i;
	output wire [63:0] counter_val_o;
	output wire [63:0] counter_val_upd_o;
	wire [63:0] counter;
	wire [CounterWidth - 1:0] counter_upd;
	reg [63:0] counter_load;
	reg we;
	reg [CounterWidth - 1:0] counter_d;
	assign counter_upd = counter[CounterWidth - 1:0] + {{CounterWidth - 1 {1'b0}}, 1'b1};
	always @(*) begin
		we = counter_we_i | counterh_we_i;
		counter_load[63:32] = counter[63:32];
		counter_load[31:0] = counter_val_i;
		if (counterh_we_i) begin
			counter_load[63:32] = counter_val_i;
			counter_load[31:0] = counter[31:0];
		end
		if (we)
			counter_d = counter_load[CounterWidth - 1:0];
		else if (counter_inc_i)
			counter_d = counter_upd[CounterWidth - 1:0];
		else
			counter_d = counter[CounterWidth - 1:0];
	end
	reg [CounterWidth - 1:0] counter_q;
	always @(posedge clk_i or negedge rst_ni)
		if (!rst_ni)
			counter_q <= 1'sb0;
		else
			counter_q <= counter_d;
	generate
		if (CounterWidth < 64) begin : g_counter_narrow
			wire [63:CounterWidth] unused_counter_load;
			assign counter[CounterWidth - 1:0] = counter_q;
			assign counter[63:CounterWidth] = 1'sb0;
			if (ProvideValUpd) begin : g_counter_val_upd_o
				assign counter_val_upd_o[CounterWidth - 1:0] = counter_upd;
			end
			else begin : g_no_counter_val_upd_o
				assign counter_val_upd_o[CounterWidth - 1:0] = 1'sb0;
			end
			assign counter_val_upd_o[63:CounterWidth] = 1'sb0;
			assign unused_counter_load = counter_load[63:CounterWidth];
		end
		else begin : g_counter_full
			assign counter = counter_q;
			if (ProvideValUpd) begin : g_counter_val_upd_o
				assign counter_val_upd_o = counter_upd;
			end
			else begin : g_no_counter_val_upd_o
				assign counter_val_upd_o = 1'sb0;
			end
		end
	endgenerate
	assign counter_val_o = counter;
endmodule