106. OCR A Level (H446) SLR15 – 1.4 D-type flip flops

What do candidates need to understand about D-type flip-flops according to the OCR clarification document?

• The history of D-type flip-flops

• The logic gates that make one up

• How to build one from scratch

• The purpose and principles of D-type flip-flops and their usage in a computer

Answer explanation

Candidates need to understand the purpose and principles of D-type flip-flops and their usage in a computer according to the OCR clarification document.

What is a true D-type flip-flop also known as?

• NAND gate flip-flop

• Basic flip-flop circuit

• Master slave D-type flip-flop

• Clock D latch circuit

Answer explanation

A true D-type flip-flop is also known as a Master slave D-type flip-flop.

What fundamental logic circuit is a building block for almost all memory devices?

• AND gate

• NAND gate

• Flip-flop

• Full adder

Answer explanation

The fundamental logic circuit that is a building block for almost all memory devices is a Flip-flop.

What type of logic gate is known as a universal logic gate?

• AND gate

• XOR gate

• OR gate

• NAND gate

Answer explanation

The NAND gate is known as a universal logic gate because it can be used to create any other type of logic gate, including AND, OR, and XOR gates.

What triggers a D-type flip-flop?

• A constant high signal

• A constant low signal

• A rising or positive edge of a clock pulse

• A falling or negative edge of a clock pulse

Answer explanation

A D-type flip-flop is triggered by a rising or positive edge of a clock pulse, making this the correct choice.

What does the output Q of a D-type flip-flop represent?

• The constant low signal

• The inverse of the clock signal

• The data input at the moment of the clock's rising edge

• The constant high signal

Answer explanation

The output Q of a D-type flip-flop represents the data input at the moment of the clock's rising edge.

What is NOT an application of D-type flip-flops?

• Shift registers

• Counters

• Power supply units

• Memory circuits

Answer explanation

The correct choice is power supply units because D-type flip-flops are not typically used in power supply units.

What is the primary function of a flip-flop?

• To amplify signals

• To perform calculations

• To convert AC to DC

• To store one bit of data

Answer explanation

The primary function of a flip-flop is to store one bit of data, making it the correct choice among the options provided.

What is the significance of the clock signal in a D-type flip-flop?

• It cools down the flip-flop during operation

• It provides power to the flip-flop

• It synchronizes the state changes facilitated by flip-flop circuits

• It determines the speed of calculations

Answer explanation

The clock signal in a D-type flip-flop synchronizes the state changes facilitated by flip-flop circuits, ensuring proper timing and functionality.

What does the NOT Q output of a D-type flip-flop represent?

• The data input

• The clock signal

• The same as the data output

• The inverse of the data output

Answer explanation

The NOT Q output of a D-type flip-flop represents the inverse of the data output, making it the correct choice.