Digital logic Design

ghz 8months ago ⋅ 217 views

To design a logic whose output is equal to input clock? Will this work using D-latch, input D will directly get clk and o/p will be equal to clk.

Is this a correct solution? If not, what are other optimal ways to design this.

Answers

Using a D-latch with the input D directly connected to the clock signal (CLK) will not result in a stable output. In digital logic design, connecting the input D directly to the clock signal can lead to unpredictable behavior known as a race condition.

A D-latch is a level-sensitive device, meaning it captures the input value (D) when the clock signal transitions from low to high (rising edge) or from high to low (falling edge). When the input D is directly connected to the clock signal, the latch may capture unpredictable values based on the timing of the signal transitions.

To design a logic circuit that generates an output equal to the input clock signal, you can use a flip-flop or an edge-triggered D-latch with proper clocking signals. Here's how you can achieve this using a positive-edge-triggered D flip-flop:

  1. Use a D flip-flop (positive-edge-triggered) or a positive-edge-triggered D-latch.
  2. Connect the clock (CLK) signal to the clock input (CLK) of the flip-flop or latch.
  3. Connect the input D of the flip-flop or latch to the desired input clock signal.

Here's a simplified representation using a positive-edge-triggered D flip-flop:

             +------------+
       CLK -->|            |
             |   D Flip-   |--> Output (Q)
   Input CLK -->|    Flop    |
             |            |
             +------------+

In this circuit:

  • The clock (CLK) signal is connected to the clock input (CLK) of the D flip-flop.
  • The input clock signal is connected to the input D of the D flip-flop.
  • On each rising edge of the clock signal (CLK), the D flip-flop captures the input value and stores it in the output (Q).

This design ensures that the output will track the input clock signal accurately, synchronizing with the clock signal transitions. Using a flip-flop or an edge-triggered latch provides a stable and predictable behavior, avoiding the issues associated with directly connecting the input D to the clock signal.

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