With the entire chip perimeter characterized we can start analyzing the logic.

• Basic logic chips are often regular with a few circuits repeated abeit in a very custom layout. How many instances of an isolated basic logic circuit are there?
  • Detail
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    • Exclude ESD protection
    • Isolated meaning that you could form N truth tables because parts of circuits do not affect others
    • Hint: think about input : output ratio and repeated layout
  1. 1
  2. 2
  3. 3
  4. 6
  5. 9
  • [3]
  • (1)
  • Using our earlier analysis we have 9 inputs and 3 outputs. This should limit the maximum number of basic logic circuits to 3. We also see that there are three triple gates. Finally, if we look at the top section of the chip, only power and ground come down. Therefore, the top section of the chip is an isolated circuit.
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