| A | B |
|---|
| DIGITAL | refers to a system where all signals take the form of discrete, specific levels, usually measured in terms of voltge. There can be any number of levels, but most commonly the number of levels is two: a high level and a low level. |
| HIGH | the higher of two voltage levels, also called “1.” |
| LOW | the lower of two voltage levels, also called “0.” |
| BINARY | a system of mathematics where there are only two numbers, 1 and 0. Usually taken to mean any system that computes or calculates using two levels. |
| ESD | electrostatic discharge |
| BASE, RADIX | the set of numbers used in a number system |
| DECIMAL | a number system based on ten digits, 0 thru 9. This is called a base 10 system. |
| BINARY | a number system based on two digits, 0 and 1. This is called a base 2 system. |
| TTL POWER SUPPLY VOLTAGE | +5VDC, always, no exceptions |
| HEXADECIMAL | a number system with a radix of 16. |
| OCTAL | a number system with a radix of 8. |
| NOT | if A is true, y is false. |
| OR | if A or B or both are true, Y is true. If A and B are false, Y is false. |
| AND | if A and B are both true, Y is true. If A or B or both are false,Y is false. |
| DATA BUS | a data path, one or more bits wide, for moving data around within a system |
| ASYNCHRONOUS | an event that is not tied to any timing signal; also circuitry that operates in this manner. |
| SYNCHRONOUS | an event that is tied to a timing signal, and does not happen until the timing signal tells it to; also circuitry that operates in this manner. |
| CLOCK | the timing signal that tells synchronous circuitry to operate. The word can mean a single clock event, or a repeating waveform that runs continuously. |
| POSITIVE-GOING CLOCK | the rising edge of a clock waveform, i.e. the transition from 0 to 1. In a schematic symbol, indicated by a triangle. |
| NEGATIVE-GOING CLOCK | the falling edge of a clock waveform, i.e. the transition from 1 to 0. In a schematic symbol, indicated by a triangle and the circle that signifies inversion |
