Multiple Choice Questions on Interfacing Techniques

The 8255 has how many programmable I/O ports?

• 1

• 2

• 3

• 4

Which mode of 8255 allows bit set/reset operations?

• Mode 0

• Mode 1

• Mode 2

• BSR Mode

In 8255, Mode 1 provides:

• Simple I/O

• Handshaking I/O

• Bidirectional Data Transfer

• Timer Operation

In 8279, the debounce logic is used for:

• Display refreshing

• Eliminating key bounce

• Serial data transfer

• Interrupt control

The 8279 can interface with how many key switches in keyboard mode?

• 32

• 64

• 128

• 256

The 8279 provides how many display output lines?

• 4

• 8

• 16

• 20

The ADC0808 has how many analog input channels?

• 2

• 4

• 8

• 16

The function of the ALE pin in ADC0808 is to:

• Start conversion

• Latch address

• Provide output

• Clear interrupt

The resolution of ADC0808 is:

• 4-bit

• 6-bit

• 8-bit

• 10-bit

DAC0808 converts:

• Digital signal to analog

• Analog signal to digital

• Parallel signal to serial

• Voltage to frequency