AIM:
To implement T flipflop using verilog and validating their functionality using their functional tables
SOFTWARE REQUIRED:
Quartus prime
THEORY
T Flip-Flop
T flip-flop is the simplified version of JK flip-flop. It is obtained by connecting the same input ‘T’ to both inputs of JK flip-flop. It operates with only positive clock transitions or negative clock transitions. The circuit diagram of T flip-flop is shown in the following figure.
This circuit has single input T and two outputs Qtt & Qtt’. The operation of T flip-flop is same as that of JK flip-flop. Here, we considered the inputs of JK flip-flop as J = T and K = T in order to utilize the modified JK flip-flop for 2 combinations of inputs. So, we eliminated the other two combinations of J & K, for which those two values are complement to each other in T flip-flop. The following table shows the state table of T flip-flop.
Here, Qtt & Qt+1t+1 are present state & next state respectively. So, T flip-flop can be used for one of these two functions such as Hold, & Complement of present state based on the input conditions, when positive transition of clock signal is applied. The following table shows the characteristic table of T flip-flop. Inputs Present State Next State
From the above characteristic table, we can directly write the next state equation as Q(t+1)=T′Q(t)+TQ(t)′ ⇒Q(t+1)=T⊕Q(t)
Procedure
1.Define Module: Define a Verilog module for the T flip-flop with inputs (T, CLK) and outputs (Q, Q_bar).
2.Declare Inputs and Outputs: Declare input and output ports for the module.
3.Implement Flip-Flop Logic: Write Verilog code to implement the T flip-flop logic based on its functional table. Use a synchronous always @(posedge CLK) block to trigger the flip-flop on the positive edge of the clock signal.
4.Simulate Using Testbench: Write a Verilog testbench to simulate the behavior of the T flip-flop under different input conditions.
5.Apply Input Stimuli: In the testbench, apply various combinations of input stimuli (T, CLK) to cover all possible input states.
6.Verify Output Behavior: Verify that the output behavior of the T flip-flop matches the expected behavior defined by its functional table.
7.Check for Race Conditions: Ensure that there are no race conditions or undefined states in the design by analyzing the timing and sequence of input changes.
PROGRAM
/* Program for flipflops and verify its truth table in quartus using Verilog programming.
Developed by: JANANI S
RegisterNumber: 212223230086 */
module TFLIPFLOPPOSEDGE( input clk, rst_n, input t,
output reg q,
output q_bar
);
always@(posedge clk)
begin
if(!rst_n)
q<=0;
else
if(t)
q<=~q;
else
q<=q;
end
assign q_bar = ~q;
endmodule
RTL LOGIC FOR FLIPFLOPS
TIMING DIGRAMS FOR FLIP FLOPS
RESULTS
Hence, T flipflop using verilog and validating their functionality using their functional tables is implemented.