Topic 8: Encoder

A encoder typically has

• More inputs than outputs

• More outputs than inputs

• An equal number of inputs and outputs

• 
  Only one input and one output

A full sized keyboard encoder used to encode 105 keys will have how many output lines?

• 5 output lines

• 6 output lines

• 7 output lines

• 8 output lines

Refer to the figure. The outputs of the decimal-to-BCD 74147 priority encoder are active low. What is the output if A4 and A8 are both high?

• 1000

• 0111

• 0100

• 1011

What is the opposite process of encoding?

• Decoding

• Multiplexing

• Demultiplexing

• Modulation

What does an encoder produce based on the activated input?

• Hexadecimal code

• N-bit input code

• Binary code

• Octal code

What does a priority encoder ensure when multiple inputs are activated?

• Output code corresponds to the lowest numbered input

• Output code corresponds to the highest numbered input

• Output code corresponds to the average of inputs

• Output code corresponds to a random input

What function does an octal-to-binary encoder perform?

• Accepts octal input and produces binary output

• Accepts 3-bit input code and activates one of eight outputs

• Accepts eight input lines and produces a 3-bit output code

• Accepts binary input and produces octal output

What is the purpose of a decimal-to-BCD priority encoder (74147)?

• Converts decimal numbers to BCD numbers

• Converts binary numbers to decimal numbers

• Converts octal numbers to binary numbers

• Converts BCD numbers to decimal numbers

What is the output code when A3 and A5 are simultaneously LOW?

• 0011

• 1100

• 0101

• 1010

What is the output code when A6, A2, and A0 are all LOW in a priority encoder?

• 0000

• 0010

• 1001

• 0110