/*
 *       metrics.v
 *       
 *   Copyright (C) 2018, 2019 Mind Chasers Inc.
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 *
 *	function: Collect metrics here and register them for transmit
 *
 *		
 */
 
`timescale 1ns /10ps

module metrics(
		input rstn,
		input clk,
		input mode_100Mbit,

		// input data for gathering metrics
		input [3:0] rx_mac_keep,
		input rx_pf_keep_01,
		input rx_pf_keep_02,
		input rx_pf_keep_10,
		input rx_pf_keep_12,
		input rx_pf_keep_20,
		input rx_pf_keep_21,
		input rx_pf_keep_23,
	
		input [3:0] rx_eop, 
		input [3:0] rx_sop,
		input [3:0] tx_eop,
		input [3:0] tx_sop,
		
		// metric outputs
		input metrics_start,
		output reg [8:0] metrics_d
);
	
reg [7:0] rx_pkt_cnt;
reg [7:0] tx_pkt_cnt;

reg [7:0] rx0_drop_cnt;
reg [7:0] rx1_drop_cnt;

reg [3:0] bit_cnt;
reg [3:0] addr;

always @(posedge clk or negedge rstn)
	if (!rstn) begin
		bit_cnt <= 4'h0;
		addr <= 4'h0;
		end
	else if ( metrics_start ) begin
		bit_cnt <= 4'h0;
		addr <= 4'h0;
		end
	else if ( !mode_100Mbit || ( mode_100Mbit && bit_cnt == 4'h9 ) ) begin
		bit_cnt <= 4'h0;
		addr <= addr + 1;
		end
	else 
		bit_cnt <= bit_cnt + 1;
		
always @(posedge clk or negedge rstn)
	if (!rstn)
		rx_pkt_cnt <= 'h0;
	else if (rx_eop[2])
		rx_pkt_cnt <= rx_pkt_cnt + 1;
		
always @(posedge clk or negedge rstn)
	if (!rstn)
		tx_pkt_cnt <= 'h0;
	else if (tx_eop[2])
		tx_pkt_cnt <= tx_pkt_cnt + 1;
	
always @(posedge clk or negedge rstn)
	if (!rstn)
		metrics_d <= 9'h100;
	else begin
		case(addr)
			'h0: metrics_d <=  { 1'b0, rx_pkt_cnt };
			'h1: metrics_d <=  { 1'b0, tx_pkt_cnt };
			'h2: metrics_d <=  { 1'b0, rx0_drop_cnt };
			'h3: metrics_d <=  { 1'b1, rx1_drop_cnt };
			default: metrics_d <= 9'h100;
		endcase
	end
		


endmodule