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/******************************************************************************
 *                                                                            *
 * This module read data from the Audio ADC on the Altera DE2 board.          *
 *                                                                            *
 ******************************************************************************/

module altera_up_audio_in_deserializer (
	// Inputs
	clk,
	reset,
	
	bit_clk_rising_edge,
	bit_clk_falling_edge,
	left_right_clk_rising_edge,
	left_right_clk_falling_edge,

	done_channel_sync,

	serial_audio_in_data,

	read_left_audio_data_en,
	read_right_audio_data_en,

	// Bidirectionals

	// Outputs
	left_audio_fifo_read_space,
	right_audio_fifo_read_space,

	left_channel_data,
	right_channel_data
);

/*****************************************************************************
 *                           Parameter Declarations                          *
 *****************************************************************************/

parameter AUDIO_DATA_WIDTH	= 16;
parameter BIT_COUNTER_INIT	= 5'h0F;

/*****************************************************************************
 *                             Port Declarations                             *
 *****************************************************************************/
// Inputs
input				clk;
input				reset;

input				bit_clk_rising_edge;
input				bit_clk_falling_edge;
input				left_right_clk_rising_edge;
input				left_right_clk_falling_edge;

input				done_channel_sync;

input				serial_audio_in_data;

input				read_left_audio_data_en;
input				read_right_audio_data_en;

// Bidirectionals

// Outputs
output	reg	[7:0]	left_audio_fifo_read_space;
output	reg	[7:0]	right_audio_fifo_read_space;

output		[AUDIO_DATA_WIDTH:1]	left_channel_data;
output		[AUDIO_DATA_WIDTH:1]	right_channel_data;

/*****************************************************************************
 *                 Internal wires and registers Declarations                 *
 *****************************************************************************/
// Internal Wires
wire				valid_audio_input;

wire				left_channel_fifo_is_empty;
wire				right_channel_fifo_is_empty;

wire				left_channel_fifo_is_full;
wire				right_channel_fifo_is_full;

wire		[6:0]	left_channel_fifo_used;
wire		[6:0]	right_channel_fifo_used;

// Internal Registers
reg			[AUDIO_DATA_WIDTH:1]	data_in_shift_reg;

// State Machine Registers


/*****************************************************************************
 *                         Finite State Machine(s)                           *
 *****************************************************************************/


/*****************************************************************************
 *                             Sequential logic                              *
 *****************************************************************************/

always @(posedge clk)
begin
	if (reset == 1'b1)
		left_audio_fifo_read_space			<= 8'h00;
	else
	begin
		left_audio_fifo_read_space[7]		<= left_channel_fifo_is_full;
		left_audio_fifo_read_space[6:0]		<= left_channel_fifo_used;
	end
end

always @(posedge clk)
begin
	if (reset == 1'b1)
		right_audio_fifo_read_space			<= 8'h00;
	else
	begin
		right_audio_fifo_read_space[7]		<= right_channel_fifo_is_full;
		right_audio_fifo_read_space[6:0]	<= right_channel_fifo_used;
	end
end




always @(posedge clk)
begin
	if (reset == 1'b1)
		data_in_shift_reg	<= {AUDIO_DATA_WIDTH{1'b0}};
	else if (bit_clk_rising_edge & valid_audio_input)
		data_in_shift_reg	<= 
			{data_in_shift_reg[(AUDIO_DATA_WIDTH - 1):1], 
			 serial_audio_in_data};
end

/*****************************************************************************
 *                            Combinational logic                            *
 *****************************************************************************/


/*****************************************************************************
 *                              Internal Modules                             *
 *****************************************************************************/

altera_up_audio_bit_counter Audio_Out_Bit_Counter (
	// Inputs
	.clk							(clk),
	.reset							(reset),
	
	.bit_clk_rising_edge			(bit_clk_rising_edge),
	.bit_clk_falling_edge			(bit_clk_falling_edge),
	.left_right_clk_rising_edge		(left_right_clk_rising_edge),
	.left_right_clk_falling_edge	(left_right_clk_falling_edge),

	// Bidirectionals

	// Outputs
	.counting						(valid_audio_input)
);
defparam 
	Audio_Out_Bit_Counter.BIT_COUNTER_INIT	= BIT_COUNTER_INIT;

altera_up_sync_fifo Audio_In_Left_Channel_FIFO(
	// Inputs
	.clk			(clk),
	.reset			(reset),

	.write_en		(left_right_clk_falling_edge & ~left_channel_fifo_is_full & done_channel_sync),
	.write_data		(data_in_shift_reg),

	.read_en		(read_left_audio_data_en & ~left_channel_fifo_is_empty),
	
	// Bidirectionals

	// Outputs
	.fifo_is_empty	(left_channel_fifo_is_empty),
	.fifo_is_full	(left_channel_fifo_is_full),
	.words_used		(left_channel_fifo_used),

	.read_data		(left_channel_data)
);
defparam 
	Audio_In_Left_Channel_FIFO.DATA_WIDTH	= AUDIO_DATA_WIDTH,
	Audio_In_Left_Channel_FIFO.DATA_DEPTH	= 128,
	Audio_In_Left_Channel_FIFO.ADDR_WIDTH	= 7;

altera_up_sync_fifo Audio_In_Right_Channel_FIFO(
	// Inputs
	.clk			(clk),
	.reset			(reset),

	.write_en		(left_right_clk_rising_edge & ~right_channel_fifo_is_full & done_channel_sync),
	.write_data		(data_in_shift_reg),

	.read_en		(read_right_audio_data_en & ~right_channel_fifo_is_empty),
	
	// Bidirectionals

	// Outputs
	.fifo_is_empty	(right_channel_fifo_is_empty),
	.fifo_is_full	(right_channel_fifo_is_full),
	.words_used		(right_channel_fifo_used),

	.read_data		(right_channel_data)
);
defparam 
	Audio_In_Right_Channel_FIFO.DATA_WIDTH	= AUDIO_DATA_WIDTH,
	Audio_In_Right_Channel_FIFO.DATA_DEPTH	= 128,
	Audio_In_Right_Channel_FIFO.ADDR_WIDTH	= 7;

endmodule

