In the previous module you came up with the pin numbering scheme and identified power and ground. Now we'll go a little deeper to figure out data flow.
Identify inputs
A
B
C
D
E
[1|4|5]
(1)
Anything with a fat transistor near the pad not connected to a gate is a pretty clear output or possibly tri-state. I highlighted a gate on each questioned input, although keep in mind that simply having a gate attached to a pin doesn't make it an input as the circuit can have feedback or tri-state (necessary but not sufficient). Going through each pin you see that each is either connected to only gates or only source/drain. We can now identify all pins as either power, input or output. D had to be traced to the other side of the die and is the lowest circled gate.