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Digital Design

What is Multiplexer(Mux) in Digital Circuits, and How It Can Be Designed?

Introduction Multiplexer digital (digital) circuit is also known as “combiner or data selector”. These circuits selects one of the input from multiple inputs and transfer it directly to output. For example, you don’t want two different input signals entering your circuit at the same time, or you want to establish a hierarchical order among themselves; in this case, you will need a formation that will select one of these signals according to the condition and include it in the circuit. These formations are called multiplexers. In this context, these circuits… Daha fazlasını oku »What is Multiplexer(Mux) in Digital Circuits, and How It Can Be Designed?

How to Use txt files in VHDL Test Bench?

Introduction While testing a VHDL module, the declared input/output ports should be tested as much as possible against all possible scenarios. For example, if a module you are designing has 5 input and 1 output ports, all input signal combinations that can enter these ports should be tested for a completely reliable design. However, the number of input combinations can reach hundreds of thousands, maybe millions for some designs. Of course, it is not possible for us to consider all combinations for these situations. Different methodologies are applied for such… Daha fazlasını oku »How to Use txt files in VHDL Test Bench?

Design of D-Flip-Flop (Schmeatic & VHDL)

Introduction For example; If we want to store 1 byte (8-bit) data in our digital circuit, we can create structures called registers by adding 8 FFs one after the other. So why do we need a memory unit with a capacity of 1-bit, 8-bit, 10-bit or 20-bit? Let’s take an example to make it more concrete: you have a device in your hand and this device transfers information such as temperature, altitude, time to your FPGA card via any interface. You want to store or use this information somewhere on… Daha fazlasını oku »Design of D-Flip-Flop (Schmeatic & VHDL)

VHDL Rising Edge Detection

If you are writing a VHDL submodule and want to detect the rising edge of a specific signal, you may think that “rising_edge(my_signal)” or “my_signal’event and my_signal = ‘1’” logics come through this issue. Nevertheless, this function works only for external clock signals. If you make a definition in the code like “rising_edge(my_signal)” or “(my_signal’event and my_signal = ‘1’)”, your HDL code will not work as you wanted. Therefore, to find the rising edge, it would be better to start with the following VHDL code. VHDL Module Design Testbench Simulation… Daha fazlasını oku »VHDL Rising Edge Detection