What is control of Single Flip-Flops?

Flip flops are an application of logic gates. A flip-flop is a basic memory element that can save one bit of data. Flip flop has two stable states. One of the stable states is called SET or 1. The other stable state is known as RESET, CLEAR, or 0.

A flip-flop circuit can stay in a binary state continually (as long as power is transferred to the circuit) before conducted by an input signal to switch states. The control gates for the seven flip-flops can be determined similarly. For example, the table shows that IEN may change as a result of the two instructions ION and IOF.

pB₇: IEN ← 1

pB₆: IEN ← 0

where p = D₇IT₃ B₇ and B₆ and are bits 7 and 6 of lR, respectively. Moreover, at the end of the interrupt cycle, lEN is cleared to 0.

RT₂ : IEN ← 0

If we use a JK flip-flip for IEN, the control gate logic will be as shown in the figure.

IEN refers to interrupt enable flag.

For the first two inputs, the value is considered as Input/output instruction. The third input is an interrupt.