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Stick diagrams can also be used to plan
out a circuit. For example, the XOR circuit in section 8.

In previous sections, the stick diagram
for the NAND, NOR, and INVERTER were already created.

When drawing a circuit, space is always a
prime concern. To reduce space, the diffusion should be broken as little as
possible, and power connections should be shared as often as possible. With VSS
and VCC power connections directly over each other, they can be shared between
logic gates to same space.
Interconnect should also be short. The
NAND gate goes directly into the INVERTER. This INVERTER is an input for one NOR
gate, who's other input is the second NOR gate.
NAND --> INV --> NOR <-- NOR
And remember that each stick diagram can
be "flipped." Keeping this in mind, first place the stick diagrams down without
interconnect. Just share the power at first, trying to match the above planned
order.

Now connect the circuit. Notice how the
output of the NAND gate is the input for the INVERTER. Also notice that one NOR
gate has that INVERTER as one of it's inputs, and the other input is another NOR
gate.

This is the finished stick diagram. We
were forced to break each diffusion once, but share the power. The interconnect
is also nice and short.
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