How do you write Xnor in VHDL?
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How do you write Xnor in VHDL?
The basic “xnor” gate: truth table equation symbol a b | c —-+– c <= a xnor b; VHDL c <= not(a xor b); 0 0 | 1 0 1 | 0 c = ~ (a ^ b); 1 0 | 0 1 1 | 1 c = xnor(a,b) Easy way to remember: “xnor” reads “not xor”, equality or even parity.
How many NAND gates are required for Xnor?
An XNOR gate circuit can be made from four NOR gates. In fact, both NAND and NOR gates are so-called “universal gates” and any logical function can be constructed from either NAND logic or NOR logic alone.
What is the Xnor operator?
The connective in logic corresponding to the exclusive nor operation. XNOR is equivalent to. , where denotes AND, denotes OR, and. denotes NOT.
What is the equation of XNOR gate?
XNOR: the Boolean expression for the XNOR gate is: \(Y = A \cdot B + \bar A\bar B\).
What is std_logic?
Std_logic signals represent one data bit and std_logic_vector represents several data bits. The signal assignments for standard logic and standard logic vector data types are shown in Example 1-15. The number of data bits for a std_logic_vector is defined in the signal assignment statement.
What does => mean in VHDL?
assignment operator
<= represents the assignment operator while => is used in the case statement, for example: case sel is when “01” => line <= “1”; when others => line <= “0”; end case. sets line to “1” in case sel is “01” and to “0” otherwise. => is also used in structural code in port maps.
How do you make an up counter counter?
To convert the up counter in Fig. 5.6. 1 to count DOWN instead, is simply a matter of modifying the connections between the flip-flops. By taking both the output lines and the CK pulse for the next flip-flop in sequence from the Q output as shown in Fig.
What is up and down counter?
Bidirectional counters, also known as Up/Down counters, are capable of counting in either direction through any given count sequence and they can be reversed at any point within their count sequence by using an additional control input as shown below.
