`include "../VX_define.vh"

module VX_csr_data (
	input wire clk,    // Clock
	input wire reset,

	input wire[`CSR_ADDR_SIZE-1:0]  read_csr_address_i,
	input wire           			write_valid_i,
	input wire[`CSR_WIDTH-1:0]      write_csr_data_i,

`IGNORE_WARNINGS_BEGIN
    // We use a smaller storage for CSRs than the standard 4KB in RISC-V
	input wire[`CSR_ADDR_SIZE-1:0]	write_csr_address_i,
`IGNORE_WARNINGS_END

	output wire[31:0]    read_csr_data_o,

	// For instruction retire counting
	input wire           writeback_valid_i
);
	// wire[`NUM_THREADS-1:0][31:0] thread_ids;
	// wire[`NUM_THREADS-1:0][31:0] warp_ids;

	// genvar cur_t;
	// for (cur_t = 0; cur_t < `NUM_THREADS; cur_t = cur_t + 1) begin
	// 	assign thread_ids[cur_t] = cur_t;
	// end

	// genvar cur_tw;
	// for (cur_tw = 0; cur_tw < `NUM_THREADS; cur_tw = cur_tw + 1) begin
	// 	assign warp_ids[cur_tw] = {{(31-`NW_BITS-1){1'b0}}, in_read_warp_num};
	// end

	reg [`CSR_WIDTH-1:0] csr[`NUM_CSRS-1:0];

	reg [63:0] cycle;
	reg [63:0] instret;

	wire read_cycle;
	wire read_cycleh;
	wire read_instret;
	wire read_instreth;

	assign read_cycle       = read_csr_address_i == `CSR_CYCL_L;
	assign read_cycleh      = read_csr_address_i == `CSR_CYCL_H;
	assign read_instret     = read_csr_address_i == `CSR_INST_L;
	assign read_instreth	= read_csr_address_i == `CSR_INST_H;

	wire [$clog2(`NUM_CSRS)-1:0] read_addr, write_addr;

	// cast address to physical CSR range
	assign read_addr = $size(read_addr)'(read_csr_address_i);
	assign write_addr = $size(write_addr)'(write_csr_address_i);

	// wire thread_select        = read_csr_address_i == 12'h20;
	// wire warp_select          = read_csr_address_i == 12'h21;

	// assign read_csr_data_o  = thread_select ? thread_ids :
	// 					          warp_select   ? warp_ids   :
	// 					          0;

	genvar curr_e;

	always @(posedge clk) begin
		if (reset) begin
			cycle   <= 0;
			instret <= 0;
		end else begin
			cycle <= cycle + 1;
			if (write_valid_i) begin
				csr[write_addr] <= write_csr_data_i;
			end
			if (writeback_valid_i) begin
				instret <= instret + 1;
			end
		end
	end

	assign read_csr_data_o =  read_cycle    ? cycle[31:0] :
								read_cycleh   ? cycle[63:32] :
								read_instret  ? instret[31:0] :
								read_instreth ? instret[63:32] :
												{{20{1'b0}}, csr[read_addr]};
endmodule : VX_csr_data