convUnit

`timescale 100 ns / 10 ps

module convUnit(clk,reset,image,filter,result);

parameter DATA_WIDTH = 16;
parameter D = 3; //depth of the filter
parameter F = 3; //size of the filter

input clk, reset;
input [D*F*F*DATA_WIDTH-1:0]image;
input [D*F*F*DATA_WIDTH-1:0]filter;

output reg [DATA_WIDTH-1:0] result;

reg [DATA_WIDTH-1:0] selectedInput1, selectedInput2;
wire [DATA_WIDTH-1:0] multResult;
wire [DATA_WIDTH-1:0] addResult;
integer i;


floatMult FM (selectedInput1,selectedInput2,multResult);
floatAdd FADD (multResult,result,addResult);


// The convolution is calculated in a sequential process to save hardware
// The result of the element wise matrix multiplication is finished after (F*F+2) cycles (2 cycles to reset the processing element and F*F cycles to accumulate the result of the F*F multiplications) 
always @ (posedge clk, posedge reset) begin
	if (reset == 1'b1) begin // reset
		i = 1'b0;
		selectedInput1 = 1'b0;
		selectedInput2 = 1'b0;
	end else if (i >= D*F*F) begin // if the convolution is finished but we still wait for other blocks to finsih, send zeros to the conv unit (in case of pipelining)
		selectedInput1 = 1'b0;
		selectedInput2 = 1'b0;
	end else begin // send one element of the image part and one element of the filter to be multiplied and accumulated
		selectedInput1 = image[DATA_WIDTH*i+:DATA_WIDTH];
		selectedInput2 = filter[DATA_WIDTH*i+:DATA_WIDTH];
		i = i + 1;
	end
end

always @ (posedge clk or posedge reset) begin
	if (reset == 1'b1) begin
		result = 1'b0;
	end else begin
		result = addResult;
	end
end

endmodule