I2S_Audio.v

module I2S_Audio(AUD_XCK,
                 reset_n,
                 AUD_BCK,
					  AUD_DATA,
					  AUD_LRCK,
					  audiodata);
input AUD_XCK;
input reset_n;
output reg AUD_BCK;
output AUD_DATA;
output reg AUD_LRCK;
input [15:0] audiodata;


reg [7:0] bck_counter;
reg [7:0] lr_counter;
wire [7:0] bitaddr;

//generate BCK 1.536MHz
always @ (posedge AUD_XCK or negedge reset_n)
begin
       if(!reset_n)
		 begin
		    bck_counter <= 8'd0;
			 AUD_BCK     <= 1'b0;
		 end
		 else
		 begin
		    
			 if(bck_counter >= 8'd5) //div XCK by 12
			 begin
			     bck_counter <= 8'd0;
				  AUD_BCK <= ~AUD_BCK;
			 end
			 else
			   bck_counter <= bck_counter + 8'd1;
		 end
		 
end

//generate LRCK, 48kHz, at negedge of BCK

always @ (negedge AUD_BCK or negedge reset_n)
begin
       if(!reset_n)
		 begin
		    lr_counter <= 8'd0;
			 AUD_LRCK     <= 1'b0;
		 end
		 else
		 begin
		    
			 if(lr_counter >= 8'd15) //div BCK by 32
			 begin
			     lr_counter <= 8'd0;
				  AUD_LRCK <= ~AUD_LRCK;
			 end
			 else
			   lr_counter <= lr_counter + 8'd1;
		end
		 
end

//send data, input data avaible at posedge of lrclk, prepared at the posedge of bck

assign  bitaddr  = 8'd15- lr_counter;
assign  AUD_DATA = audiodata[bitaddr[3:0]];

		

endmodule