Tag: conversion

Categories
Sequential Circuits

Conversion: Generic

CONVERSION OF ONE FLIP-FLOP TO OTHER:

As we have already seen from the way we derived D flip-flop from RS flip-flop or the way we derived T flip-flop from JK flip-flop or the way we derived JK flip-flop from RS flip-flop by feeding back outputs that to derive a flip-flop from the other flip-flop we need to design a combinational arrangement before the given flip-flop to convert the given to work as required flip-flop.

Hence the general diagram to obtain a flip-flop from the given flip-flop is as:

Categories
Sequential Circuits

Conversion: D to T & T to D FF

Similar to previous conversions, we get the circuits as follow:

D FF to T FF:

T FF to D FF:

Note: We have not shown the clock but we can attach the clock signal to the given FF.

Similarly we can obtain other conversions. 

Categories
Sequential Circuits

Conversion: D to RS flip-flop

We first write the truth table for required Flip-flop i.e. RS FF

Now we write the excitation table of given FF i.e. D flip-flop as

Now we combine two tables to get the combinational circuit as:

Now we design the combinational circuit to convert J, K to corresponding R, S

K-map for D input:

And we get the circuit to convert D to SR FF:

Categories
Sequential Circuits

Conversion: RS to JK flip-flop

We first write the truth table for required Flip-flop i.e. JK FF

Now we write the excitation table of given FF SR flip-flop as

Now we combine two tables to get the combinational circuit as:

Now we design the combinational circuit to convert J, K to corresponding R, S

K-map for S input:

K-map for R input:

So we get the circuit to convert RS FF to JK FF:

Categories
Sequential Circuits

Conversion: RS to D flip-flop

Let’s first now derive the D flip-flop from RS flip-flop which we have already done:

We first write the truth table for required D flip-flop as

Now we write the excitation table of given FF SR flip-flop as

Now we need to make a arrangement so that we manipulate input D to inputs R, S such that we get the same output with RS FF as that of D FF. So we combine the two tables given above with same outputs in the same row:

Now we design the combinational circuit to convert D input to SR inputs using K-map as:

K-map for S input:

K-map for R input:

Hence we convert the SR FF to D FF as: