The diagram below shows the layout of an nMOS memory cell. The colours have their conventional meanings: blue for metal, red for polysilicon, green fo diffusion, yellow for implant and black for contact cuts. [The open black box is a buried contact linking just polysilicon and diffusion without using any metal.]
Derive a stick diagram and circuit diagram of the cell. Label the external connections and describe their purposes. Describe the memory cell's method of operation.