# Digital Systems I

## Course Description

Covers basic electrical concepts, number systems, combinational gates (AND, OR, NOT, NAND, NOR, and XOR), electrical characteristics and internal structures of TTL gates, Boolean algebra, Karnaugh mapping, and use of MSI devices including adders, decoders, encoders, multiplexes and demultiplexers. Includes a 3 hour per week laboratory. Prerequisite/concurrent: MTH 111. Audit available.

## Intended Outcomes

Upon successful completion students should be able to:

1. Describe the operation of combinational logic gates (AND, OR, NOT, NAND, NOR, and XOR) from both an electrical and a logical point-of-view and be able to combine logic gates into circuits that perform various functions.
2. Use the binary number system as well as Boolean algebra, DeMorgan’s Theorem, and Karnaugh mapping to manipulate Boolean expressions.
3. Interpret the truth tables of MSI (medium-scale integration) devices including adders, decoders, encoders, multiplexers and demultiplexers.
4. Analyze the overall circuit operation when a MSI device is combined with combinational gates, or other MSI devices, to create an application circuit.
5. Construct digital circuits using standard laboratory instrumentation to verify the operation of the circuits, and use PC-based electronic circuit simulation software.

## Outcome Assessment Strategies

Assessment methods are to be determined by the instructor. Typically, in-class quizzes, exams and weekly homework assignments will be used. Laboratory assessment will be by reports and/or practical skills testing.

## Course Content (Themes, Concepts, Issues and Skills)

1. Basic electrical concepts including voltage, current, and resistance and the use of Ohm's Law for simple circuits.
2. The decimal, binary, and hexadecimal ("hex") number systems and the conversion of numbers between the decimal system and the binary system.
3. The Boolean operations of AND, OR, NOT, NAND, NOR, and XOR in terms of their schematic symbols, Boolean equations, and truth tables.
4. The mechanical and electrical characteristics of the TTL family of logic devices including the printout of the device, the allowable power supply voltage range, allowable temperature range, input voltage specifications, output voltage specifications, and the propagation delay of the device.
5. The identities and use of Boolean algebra and the use of DeMorgan's Theorem.
6. Simplification of logic functions using Boolean algebra and Karnaugh maps.
7. The specification of the required logic to implement a desired combinational logic function where the logic has been simplified as much as possible using Boolean algebra or Karnaugh maps.
8. The use of timing diagrams to describe the response of a logic circuit to time-varying inputs.
9. MSI (medium scale integration) functions including half adders, full adders, decoders, encoders, multiplexers, and demultiplexers.
10. The use of multiplexers to implement logic functions.
11. An architectural overview of common programmable logic devices (PLDs) including the programmable read-only memory (PROM), programmable logic array (PLA), and programmable array logic (PAL).
12. The use of PC-based circuit simulation software to simulate a digital circuit.

## Department Notes

In the laboratory, the student will construct several digital circuits including a circuit that could be used to control a furnace and a circuit that lights LEDs in a specified sequence. The student will use standard laboratory instrumentation, including the oscilloscope, to verify the operation of each circuit. The student will also use PC-based electronic circuit simulation software to simulate the operation of at least one digital circuit.