Reputation: 441
I want to make a calculator based on fpga board(spartan 3). I have this following code
module bcd_converter(
input [7:0] R,
output reg [3:0] Hundreds,
output reg [3:0] Tens,
output reg [3:0] Ones
);
integer i;
always @ (R)
begin
Hundreds = 4'd0;
Tens = 4'd0;
Ones = 4'd0;
for(i=7;i>=0;i = i-1) begin
if(Hundreds >= 5)
Hundreds = Hundreds + 3;
if(Tens >= 5)
Tens = Tens + 3;
if(Ones >= 5)
Ones = Ones + 3;
Hundreds = Hundreds<<1;
Hundreds[0] = Tens[3];
Tens = Tens << 1;
Tens[0] = Ones[3];
Ones = Ones<<1;
Ones[0] = R[i];
end
end
endmodule
However, the code provided does conversion only for binary into BCD. I am looking for a way to reverse this algorithm. Is there any better way of converting BCD into binary?
Upvotes: 2
Views: 1898
Reputation: 46
You could decode each BCD digit into binary with separate case statements, and just add the results. For example, for hundreds your case statement would look like this:
case(hundreds)
4'd0 : hundreds_bin = 10'd0;
4'd1 : hundreds_bin = 10'd100;
4'd2 : hundreds_bin = 10'd200;
4'd3 : hundreds_bin = 10'd300;
//..etc etc
Upvotes: 1