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Setting J = K = 0 maintains the current state. To synthesize a D flip-flop, simply set K equal to the complement of J (input J will act as input D). Similarly, to synthesize a T flip-flop, set K equal to J. The JK flip-flop is therefore a universal flip-flop, because it can be configured to work as an SR flip-flop, a D flip-flop, or a T flip-flop.
Flip-flop excitation tables [ edit ] In order to complete the excitation table of a flip-flop , one needs to draw the Q(t) and Q(t + 1) for all possible cases (e.g., 00, 01, 10, and 11), and then make the value of flip-flop such that on giving this value, one shall receive the input as Q(t + 1) as desired.
quad D flip-flops, clear 16 SN74LS171: 74x172 1 16-bit multiple port register file (8x2) three-state: 24 SN74172: 74x173 4 quad D flip-flop, asynchronous clear three-state: 16 SN74LS173A: 74x174 6 hex D flip-flop, common asynchronous clear 16 SN74LS174: 74x175 4 quad D edge-triggered flip-flop, complementary outputs and asynchronous clear 16 ...
An asynchronous (ripple) counter is a "chain" of toggle (T) flip-flops in which the least-significant flip-flop (bit 0) is clocked by an external signal (the counter input clock), and all other flip-flops are clocked by the output of the nearest, less significant flip-flop (e.g., bit 0 clocks the bit 1 flip-flop, bit 1 clocks the bit 2 flip ...
Registers (usually implemented as D flip-flops) synchronize the circuit's operation to the edges of the clock signal, and are the only elements in the circuit that have memory properties. Combinational logic performs all the logical functions in the circuit and it typically consists of logic gates .
The circuit can be broken down into 3 parts: data-transition look ahead, pulse generator, and clock generator. The pulse generator output is fed into the clock generator which is used to clock the D flip-flop. Based on the input and output signals, if there is a need to change the state of the D flip-flop, then the clock is allowed to switch to ...
Synchronizers may take the form of a cascade of D flip-flops (e.g. the shift register in Figure 3). [7] Although each flip-flop stage adds an additional clock cycle of latency to the input data stream, each stage provides an opportunity to resolve metastability. Such synchronizers can be engineered to reduce metastability to a tolerable rate.
Here, the contamination delay is the amount of time needed for a change in the flip-flop clock input to result in the initial change at the flip-flop output (Q). If there is insufficient delay from the output of the first flip-flop to the input of the second, the input may change before the hold time has passed. Because the second flip-flop is ...