Multiple choice

Tri-state buffers are required to connect two or more I/O devices on the bus. Why do we need tri-state buffers?

  1. Tri-state buffers are not required.

  2. Tri-state buffers provide a highly resistive output when their corresponding I/O devices are not selected.

  3. Tri-state buffers are required to provide high power to the bus.

  4. Tri-state buffers create longer delays.

  5. Tri-state buffers reduce the size of the gate.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When a device is not selected and other device is selected, then the current device must leave the bus, i.e. it should remain open circuited when not selected. The highly resistive output virtually creates an open circuit situation for the device not selected. This feature is not available in normal gates. So, tri-state buffers are required.

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