What logic is inferred when there are multiple assign statements targeting the same wire for synthesis ?
The synthesis tool will give a syntax error for a wire that is an output port of a module if it is driven by more than one source.
wire out;
assign out = a & b;
// Elsewhere in the code, another assign to
// the same wire will cause multiple driver error
assign out = a | b;
What is a synchronous FIFO ?
A synchronous FIFO (First-In-First-Out) is a type of data buffer used in digital systems that operates under a single clock domain, meaning both read and write operations occur using the same clock signal. This design ensures that data is processed in the order it was received, which is critical for maintaining data integrity in various applications.
A synchronous FIFO is called "synchronous" because it uses synchronized clocks to control the read and write operations. The read and write pointers of the FIFO are updated synchronously with the clocks, and data is transferred between the FIFO and the external circuit synchronously with the clocks.
Synchronous FIFOs are primarily used to buffer data when the rate of data transfer exceeds the rate of data processing. This is particularly important in high-speed systems where timing discrepancies can lead to data loss or corruption.
Gray code is a binary code where each successive value differs from the previous value by only one bit.
Implementation #1
module bin2gray #(parameter N=4) ( input [N-1:0] bin,
output [N-1:0] gray);
genvar i;
generate
for(i = 0; i < N-1; i = i + 1) begin
assign gray[i] = bin[i] ^ bin[i+1];
end
endgenerate
assign gray[N-1] = bin[N-1];
endmodule
Gray code, also known as Gray binary code or reflected binary code, is a binary numeral system where adjacent values differ by only one bit. In other words, Gray code is a binary code where each successive value differs from the previous value by only one bit.
For example, the binary representation of decimal numbers 1 and 2 is 0001 and 0010 respectively. Note that two LSB bits (bit#0 and bit#1) have to change for the transition from 1 to 2. In Gray code, 1 and 2 are represented by 0001 and 0011 respectively but the same transition now requires only a change of one bit (bit#1 from LSB).
A shift register is a sequential digital circuit that is used to store and transfer binary data. It consists of a series of flip-flops connected in a chain, with each flip-flop holding a single bit of data. The input data is shifted through the register one bit at a time, either left or right, depending on the design.
