EE481 Logical Design Lab
Fall 2003, Lab #8

Prelab Questions

1. Calculate the throughput for memory reads for the following different memories:
   • EPROM, ta = 250 ns.
   • DRAM, ta = 100 ns.
   • Enhanced DRAM, ta = 50 ns.
   • Cache SRAM, 10 ns.
   (Hint: The timing diagram found in the memory basics web-page may be helpful.)

2. a) Calculate the transfer rate for the LCD module. Be sure to include any processing time required by LCD.
   b) Is this rate fast enough to process the maximum data transfer rate of the parallel port found in lab #6?

Experiments

1. Your task is to design and implement a logic circuit that controls two data sources and a display. Both data sources are sharing the same display unit, which is a 16-character, liquid-crystal dot-matrix display (LCD). The data sources for this particular experiment are a parallel port and a non-volatile memory. A user will be able to select which data source is to control the display. Data in the computer can be modified by the user, however, the data in the memory will be written before-hand. Writing to the Flash memory is not a part of this experiment.

   You are to design the following circuit and show your TA what was written into the memory and what you can send from the computer. You can use PALs and/or discrete logic for any part of this lab.

NOTE-1: Check out the timing diagram to see how data transfer and control signal events occur during a session.

NOTE-2: Check out external information about memory basics.

NOTE-3: Check out external information about Liquid Crystal Display Unit.

NOTE-4: Socket pin descriptions: