Monday, September 22, 2003		ITerminology

Breakpoint: The location in programming code that, when reached, triggers a temporary halt in the program. Programmers use breakpoints to test and debug programs by causing the program to stop at scheduled intervals so that the status of the program can be examined in stages.

ICE: Also known as In-Circuit Emulator, it is a computer chip used to emulate a microprocessor so that embedded system software can be tested by developers. The processor that the hardware device’s software is going to run on is replaced with an ICE that acts just as the processor would. ICEs enable developers to closely monitor the development of an embedded system and are useful tools for debugging.

PLC: Short for power line communications, the use of the existing utility power grid as the medium to send broadband data communications. In theory, plugging a computer device into an existing power outlet would connect the user to the Internet by tapping into already established national and global power grid networks. Power grids typically transmit electricity in three levels of voltage: low, medium and high. Medium voltage, typically ranging in the tens of thousands of volts, is what a utility substation will bring to a transformer, and the transformer will reduce the voltage into the low range before sending the electricity into a building.

DAA: Data Access Arrangement, part of a modem’s system for interfacing with a telephone network. The DAA provides the analog circuits that electrically isolate the modem from the phone line, separating the modem from the telephone line’s higher voltage. The FCC requires this feature of any device that connects to the PSTN, including fax machines and set-top boxes, and most manufacturers build modems around an FCC-approved DAA design.