CSCI 255, ENGR 274, ECE 212 -- 28 September, 2000


MSI-like components

CMOS transmission gates

Open-collector gates

"In general, open-collector gates and tri-state gates are used for the same kinds of functions. But tri-states are more economical because they do not require the external resistor. They have largely replaced open-colector gates in modern designs." -- textbook, p. 210

Tri-state devices

  1. 0
  2. 1
  3. Z -- high impedance state

Read-only memories (ROM)

Writing the ROM

Little ROMs to big ROMs