`timescale 1ns / 1ps
//////////////////////////////////////////////////////////////////////////////////
// Company:
// Engineer: Larry Qu
//
// Create Date:    23:26:35 01/13/2020
// Design Name:
// Module Name:    swcounter
// Project Name:
// Target Devices:
// Tool versions:
// Description:
//
// Dependencies:
//
// Revision:
// Revision 0.01 - File Created
// Additional Comments:
//
//////////////////////////////////////////////////////////////////////////////////
module swcounter(
			//inputs
			SEL, ADJ, RST_S, PSE_S, CLK1, CLK2,

			//outputs
			M_H, M_L, S_H, S_L
			//seconds
    );


	output reg[2:0] M_H = 3'b0; //tens digit of minutes
   output reg[3:0] M_L = 4'b0; //ones digit of minutes
	output reg[2:0] S_H = 3'b0; //tens digit of seconds
   output reg[3:0] S_L = 4'b0; //ones digit of seconds


   input SEL; //select button
   input ADJ; //adjust button
	input RST_S; //reset button
   input PSE_S; //pause button
	input CLK1; //1 Hz clock
   input CLK2; //2 Hz clock

	//output[11:0] seconds;
	//reg[11:0] seconds = 12'b0; //register to store 0 to 3599

	reg[0:0] pause = 1'b0; //register to store pause value

	//use one always block for everything, use conditionals to separate
	always @(posedge PSE_S or posedge RST_S or posedge CLK1 or posedge CLK2)
	begin
		//if pause button is hit
		if(PSE_S)
		begin
			pause <= ~pause;
		end

		//if reset button is hit
		else if(RST_S)
		begin
			S_L <= 4'b0;
			S_H <= 3'b0;
			M_L <= 4'b0;
			M_H <= 3'b0;
		end


		//if adjustment is high, run adjustment mode
		else if(ADJ && !pause && CLK2)
		begin
			//if(!pause && CLK2) //if not paused and adj is selected, enter adjustment mode, otherwise do nothing
			//begin
				if(SEL) //is SEL == 1, then increment seconds, otherwise increment minutes
				begin
					if (M_H == 3'b101 && M_L == 4'b1001 && S_H == 3'b101 && S_L == 4'b1000) //if we hit 59:59, pause
					begin
						S_L = 4'b1001;
						pause <= 1'b1;
					end
					else
					begin
						if(S_L == 4'b1001) //otherwise, increment
						begin
							S_L = 4'b0;
							if(S_H == 3'b101) //seconds high
							begin
								S_H = 3'b0;
								if(M_L == 4'b1001) //minutes low
								begin
									M_L = 4'b0;
									if(M_H == 3'b101) //minutes high
									begin
										pause = 1;
									end
									else
									begin
										M_H = M_H + 1;
									end
								end
								else
								begin
									M_L = M_L + 1;
								end
							end
							else
							begin
								S_H = S_H + 1;
							end
						end
						else
						begin
							S_L = S_L + 1;
						end
					end
					if (M_H == 3'b101 && M_L == 4'b1001 && S_H == 3'b101 && S_L == 4'b1000) //if we hit 59:59, pause
					begin
						S_L = 4'b1001;
						pause <= 1'b1;
					end
					else
					begin
						if(S_L == 4'b1001) //otherwise, increment
						begin
							S_L = 4'b0;
							if(S_H == 3'b101) //seconds high
							begin
								S_H = 3'b0;
								if(M_L == 4'b1001) //minutes low
								begin
									M_L = 4'b0;
									if(M_H == 3'b101) //minutes high
									begin
										pause = 1;
									end
									else
									begin
										M_H = M_H + 1;
									end
								end
								else
								begin
									M_L = M_L + 1;
								end
							end
							else
							begin
								S_H = S_H + 1;
							end
						end
						else
						begin
							S_L = S_L + 1;
						end
					end
				end
				else
				begin
					if (M_H == 3'b101 && (M_L == 4'b1001)  ) //if we hit 58:xx or 59:xx, pause
					begin
						M_L = 4'b1001;
						pause <= 1'b1;
					end
					else
					begin
						if(M_L == 4'b1000) //minutes low
						begin
							M_L = 4'b0;
							if(M_H == 3'b101) //minutes high
							begin
								pause = 1;
							end
							else
							begin
								M_H = M_H + 1;
							end
						end
						else
						begin
							M_L = M_L + 1;
						end
					end
					if (M_H == 3'b101 && (M_L == 4'b1001)  ) //if we hit 58:xx or 59:xx, pause
					begin
						M_L = 4'b1001;
						pause <= 1'b1;
					end
					else
					begin
						if(M_L == 4'b1000) //minutes low
						begin
							M_L = 4'b0;
							if(M_H == 3'b101) //minutes high
							begin
								pause = 1;
							end
							else
							begin
								M_H = M_H + 1;
							end
						end
						else
						begin
							M_L = M_L + 1;
						end
					end
				end
			//end
		end


		//otherwise run normally on regular clock pulse
		else if(!ADJ && CLK1 && !pause)
		begin
			//if(!pause && !ADJ) //if not paused and not in adjustment mode, run normally
			//begin
				if (M_H == 3'b101 && M_L == 4'b1001 && S_H == 3'b101 && S_L == 4'b1000) //if we hit 59:59, pause
				begin
					S_L = 4'b1001;
					pause <= 1'b1;
				end
				else
				begin
					if(S_L == 4'b1001) //otherwise, increment
					begin
						S_L = 4'b0;
						if(S_H == 3'b101) //seconds high
						begin
							S_H = 3'b0;
							if(M_L == 4'b1001) //minutes low
							begin
								M_L = 4'b0;
								if(M_H == 3'b101) //minutes high
								begin
									pause = 1;
								end
								else
								begin
									M_H = M_H + 1;
								end
							end
							else
							begin
								M_L = M_L + 1;
							end
						end
						else
						begin
							S_H = S_H + 1;
						end
					end
					else
					begin
						S_L = S_L + 1;
					end
				end
			//end
		end

		else
		begin
		end

	end

	/*
	//pause button
	always @(posedge PSE_S) //every time we press the pause button, change value of pause
	begin
		pause <= ~pause;
	end
	*/

	/*
	//reset button
	always @(posedge RST_S)
	begin
		seconds <= 12'b0;
	end
	*/

	/*
	//standard counting
	always @(posedge CLK1)
	begin
		if(!pause && !ADJ) //if not paused and not in adjustment mode, run normally
		begin
			if (seconds == 12'b111000001111) //if we hit 59:59, pause
			begin
				seconds <= seconds;
				pause <= 1'b1;
			end
			else
			begin
				seconds <= seconds + 1; //otherwise, increment
			end
		end
	end
	*/

	/*
	//fast counting for adjustment, always clk2, use enable
	always @(posedge CLK2)
	begin
		if(!pause && ADJ) //if not paused and adj is selected, enter adjustment mode, otherwise do nothing
		begin
			if(SEL) //is SEL == 1, then increment seconds, otherwise increment minutes
			begin
				seconds <= seconds + 2;
				if (seconds >= 12'b111000001111) //if we hit 59:59, pause
				begin
					seconds <= 12'b111000001111;
					pause <= 1'b1;
				end
			end
			else
			begin
				seconds <= seconds + 60;
				if (seconds >= 12'b111000001111) //if we hit 59:59, pause
				begin
					seconds <= 12'b111000001111;
					pause <= 1'b1;
				end
			end
		end
	end
	*/

endmodule