Chip Directory
Mirror sites
Mailing list
Have this site translated
 Datasheet Archive
 Embedded Systems
Host site

ABC of electronics terms

Click on the first letter of the electronic term you're looking for:
0..9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

(To find chips for distinct functions, see the functional pages.)



See Packaging


Where Manufacturer Xymox Technologies

Parallel port

The parallel printer port on the PC, also called Centronics port.

See local.

Patent The patent data base (set up by IBM). Patents in Australia Chip patents at the Smithsonian Institute


Personal Computer

local IBM PC specific information for hardware and software developers PC Hardware FAQ and the Chiplist by Aad Offerman PC hardware reference site Also info about programming PC-hardware! Joystick info Overclocking CPU's and motherboards Some stuff on PC type software Cure your PC and keep it healthy! Information about components in PC Connecting IBM keyboard to 80c51 via I2C* bus

See also under Bus and on the PC page.


Printed Circuit Board

See local.


New name for the 'PCMCIA' bus definition.


Peripheral Component Interconnect (Local Bus definition from Intel)

PCI Special Interest Group
See also:
local Text about choosing simple PCI controller
local About the PCI bus by Mark Sokos PCI Special Interest Group the developers section about ordering the specifications ACPI Unofficial list of PCI device ID's by Jim Boemler Lots more PCI and AGP info PCI vendor ID's

Books about PCI

title order at Amazon USA price indication
PCI Handbook, the ISBN: 0929392256 $12
PCI Hot-Plug: Application and Design ISBN: 0929392604 $35
PCI System Architecture, Fourth Edition (PC System Architecture Series) ISBN: 0201309742 $32
PCI Bus Demystified ISBN: 187870754X $40

Books from

title order at Amazon DE price indication
PCI System Architecture, Fourth Edition (PC System Architecture Series) ISBN: 0201309742 DM 91


The SGML based Pinnacles Component Information Standard (PCIS) format developed by the Pinnacles group (Hitachi, Intel, NS, Philips, TI).

Pinnacles, the IC* document exchange group, opens membership


Richard Goering

PHOENIX -- The Pinnacles Group, an independent consortium of five semiconductor companies, is opening its membership in a bid to enhance its emerging standard for the electronic exchange of component data. To spearhead the effort, consultant Rita Glover has been named director of business development.

The original five Pinnacles member companies are Hitachi, Intel, National Semiconductor, Philips S emiconductor and Texas Instruments. Together, they've developed a Pinnacles Component Information Standard (PCIS) that allows a single data source to support CD-ROM or Internet delivery, master selection guides and faxes-on-demand. The group plans to bring its activities under the CAD* Framework Initiative (CFI) umbrella.

Voting memberships are available at two levels: the individual working group level and the project technical advisory board level, which includes a voting membership in each working group. For more information, call (602) 581-8787 or send e-mail to ECIX FAQ Another article


Pulse Code Modulation

This is the coding whereby analogue telephone data is coded logarithmically in 8 bits per sample at a sample rate of 64Kbit/s=8Kbyte/s. There are two coding standards, the European/International one called A-law and the American one called µ-law (with the u in u-law being the greek letter mu). Modern soundcards can also code using this format. The advantage of using a logarithmic coding scheme is that low-volume level and high volume level conversations can be coded with about the same precision.

See also: ADPCM* and codec*.


Personal Computer Memory Card International Association
It's the definition of the bus standard for those small memory, hard disk and modem* cards that are used in lap top computers. The new name is PC-Card.

Personal Computer Memory Card International Association
1030 East Duane Ave,
Suite G
Sunnyvale, CA 94086
tel: +1-408-720-0107
fax: +1-408-720-9416
Above info is from PC Card Standard Vol 2 Electrical Specification Document No. 0595-02-1000
PCMCIA System Architecture - Mindshare, Inc (Don Anderson), Addison-Wesley, 1995, ISBN: 0-201-40991-7 - WWW site of PCMCIA - Unofficial FAQ by David Cary


Portable Data Format (?) by Adobe.

This is the industry standard for electronic versions of datasheets.

You need Adobe's Acrobat reader for looking at these files:
The reader is for free, but the writer costs money.

Instead you can also put the URL of the PDF file in the body of a message to and if you are lucky, Adobe will send you the whole document in text form!


An interpreted programming language, Larry Wall. How PERL works At O'Reilly, (that employs Larry Wall to work on Perl full time) PHP is a less messy alternative for WWW oriented problems


The pH value of water is the measure for acidity. (How sour it is). The scale goes from 0 to 14 with 7 being the neutral value between acidic and basic. Each step on the scale means 10 times as many acidic or basic molecules. Acidity is traditionally measured with litmus paper which changes color at a certain acidity.
But of course we want to measure it electronically! About pH, conductivity and dissolved oxygen Other basic chemics stuff

Phasing error

This is a hard to understand error that a primitive assembler program gives when the addresses that it assigns to the assembled program differ between the two passes. More about this


Industrial and electronics photography They can make electronics components look attractive! Using the latest digital technologies MSP Visual Communications can produce eye-catching publicity photos of your products.

Photonics Photonics Online (By VerticalNet)

Physics Physics


Peripheral Interface Controller (?), by MicroChip, see PIC family.
Peripheral Interrupt Controller, by Intel

PIC16c84 programmer FAQ in text


Where Manufacturer Projects Unlimited Raltron



Plant Automation Plant Automation (by VerticalNet)


Where Manufacturer Bivar Plastic repair


Programmable Logic (?) Controller. This is a term from the industrial automation world. Siemens used to be big on this market here in Europe. Probably they still are. open source Linux PLC project


Programmable Logic Device

Manufacturers: Actel Altera AMD Atmel AT&T Cypress Lattice Motorola NXP (formerly Philips Semiconductors) Quicklogic Xilinx



On 20001101 Spyros Vlaxos wrote:
Hi! My name is Spyros and I would like to ask you a question about PLL*'s. Could you explain to me what a PLL* is and where it can be used?
I'm not very familiar with phase locked loop devices. I think it's a kind of square wave oscillator that can be triggered. So if it isn't triggered it will go after a while anyway, but you can trigger it once in a while so the signal will stay in phase with another frequency. Oscilloscopes use a mechanism like this for their video-beam in x-direction. Radio's and TV's also use it for locking on to a frequency that they are receiving I think. It's probably also used by two synschronous UART's to keep their clocks synchronized. Floppy controllers also use it I think to read data from the floppy. Sometimes a clock pulse is left out to signify a special bit.


Where Manufacturer Bourns Inc DuPont Chemicals Corp Rexam Graphics

Portable phone

Also called a cell phone (in the USA) or mobile phone.

Ports (on PC)

Ports are a kind of memory locations that Intel processors (and some others) use to speak to I/O chips. Other processor use a part of their normal memory. (This is called memory mapped I/O).
Here are a lot of the most used PC ports:
port description chip or device
0000 dma controller 8237A
0020 interrupt controller 8259A
0030 interrupt controller 8259A
0040 timer 8254
0050 timer 8254
0060 keyboard 8042
0070 RTC, NMI mask
0080 DMA* page registers 74LS612
0090 DMA* page registers 74LS612
00a0 interrupt controller 2 8259A
00b0 interrupt controller 2 8259A
00c0 DMA* controller 2 8237A
00d0 DMA* controller 2 8237A
00f0 math coprocessor 80287
0170 hard disk controller 2 IDE
01f0 hard disk controller 1 IDE
0200 joystick
0220 sound board
0278 lpt2
02e8 com4
02f8 com2
0300 CD-ROM interface non-IDE
0360 network board
0378 lpt1
03b0 monochrome display adapter MDA - Hercules, VGA*
03bc lpt3
03c0 Enhanced graphics adapter EGA, VGA*
03d0 Color graphics adapter CGA, VGA*
03e8 com3
03f0 floppy disk controller uPD765/8272
03f8 com1

Power IC Circuit examples

Where Manufacturer Cherry Semiconductor

For and email newsletter about Power Management ICs and Data Communication ICs by IMP, Inc. send an email to with in the body: subscribe IMP_eNews

Power Supply

Where Manufacturer Acopian Advanced Power Solutions American Power Conversion APC Astec America Bear Power Supplies, manufacture of AC/DC modular PCB mounted power supplies. Computer Products Corp Condor Power Interpoint Kepco Lambda Electronics Oryx Power Inc Power-One Unitrode VERO Electronics <> Vicor


Serial Protocol for the Internet, successor to SLIP* FAQ


Where Manufacturer Canon


local Processor history texts on the WWW Technical catalog of EDN

See also CPU, MCU and MPU.

Program (computer-) How it works


Besides being a human that writes programs it's a device to program ((E)E)PROM*'s.

local Programmer manufacturers
local NM93C46 programmer Free EPROM* programmer schematics?

In the last 3 month I had a problem with the program space of the 32K module of several MC68HC916X1 microcontrollers. After several weeks of operation time the application shuts down and couldn't restart. After checking the system I found out, that parts of the program space are erased. After reprogramming the system works fine. Than the same mistake could takes place after 1 day or 4 weeks.

Is that in EPROM* or EEPROM? Not all EPROM* programming methods are as solid as others. There are certain fast methods that aren't reliable enough (we experienced). After a while we used the slower methods instead. Basically the fast method consists of pulsing the data in several times and checking till the bit has flipped from 1 to 0, after that a couple of extra pulses are given to be 'well enough' above the threshold.
Complications are however that there may be a regression to it's former state and that this seems to be worse when the part has just been erased. Our policy was to use erased parts only for internal usage and use new parts for products. Usually it's advised to leave erased parts alone for 24 hours before reusage.
When your parts are in sockets, as I assume, also beware of corrosion etc. especially in a hostile industrial environment.
Perhaps as a test, solder a part in without socket...

Programming language

A language to program a computer, processor or controller in.

At first one had to program the computers using switches with which the binary code for each instruction was entered into each address by hand.
Then assembler was invented and programmers could write programs using mnemonics for the instructions and symbolic names for the locations.
Then Fortran was invented which made the language independent from the underlying computer. For business purposes Cobol was invented.
Fortran wasn't very elegant (nor powerful) so Algol was designed.
Algol was a very heavy language which needed very powerful compilers so the very simple languages BCPL and B were designed. The language B was the inspiration for the language C which is still heavily used and formed the basis for C++, Java, Javascript and most other modern languages.
In the mean time Wirth also tried to make a much more simple Algol and called it Pascal and later Modula. Pascal became very popular thanks to Borland and it's now part of Delphi.
BASIC was a kind of language for everyman and it became the first language of choice for the homecomputers because it was interpreted and didn't need a compiler. It also had inbuild primitive editting possibilities because the lines were numbered.
ADA was an attempt by the American Defense Department to standardize all their software. However ADA compilers were so complicated to write that the language never became very popular.
Forth is a language that is being interpreted, but the programmer is forced to think in terms of the stack which isn't easy and seems to result in unreadable programs (for humans). Since the language is expendable there are many versions around.
Lisp is also a stack oriented language but has many high-level commands which makes it very useful for AI programs. It's also quite unreadable.
I can't recall the name of the first object oriented language on which C++ and Java were based later.
Other languages were PL/1, Snobol.
Newer languages are ABC (educational), Eifel, Python.

See also: Language Lab

Project kits

local Manufacturers Bob Parker

Protection circuit Newsgroup


Where Manufacturer Vector Electronics


A Programmable System Device is a configurable memory system on a chip for embedded systems.

See: at ST (formerly by Waferscale) main page there at distributor


PSpice is PC-based software to emulate the behaviour of electronic circuits. This forum helps to find specific PSpice Models developed by vendors or individuals.

See also Spice and VHDL.


See Open-collector output.

Besides what is discussed there. Pull-up's are also useful to detect the status of jumpers and DIP-switches...


Pulse width modulation is generating a square wave with variable length up and down durations. Usually a single up+down period is of constant length, but the so called duty-cycle (the up-period) varies. When you look at the power contents of the signal compared to the voltage of the low state it will vary over time as the duty cycle varies. When you integrate the value over time, using for example just a resistor (in series) and a capacitor (in parallel) you'll have an analogue value which you can use as if it came out of an DAC. In fact you've created a very cheap serial DAC. Timer/counters of MCU's can usually generate PWM signals quite easily. Of course you can only use the signal for slow speed applications like controling the amplification of an amplifier or the brightness of a lightsource etc. but it can be very useful. Consider however that when the MCU might fail, the signal may go high or low, so make sure the signal will not damage anything (like people's ears when the signal is used to drive an audio amplifier: Been there, done that. ;-). Online training: Motor Control using PWM

Click on the first letter of the electronic term you're looking for:
0..9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Ad for PCI video capturing boards by Dektec.
Goto: Main Mirror About Author
Register: Yourself Company
Feedback: Correction Addition Question
Request quote: Chips (Deutsch) Chips (English) Chips (Nederlands)

Advertisement by Adprov

Viewable with any browser

page modified: 20080226
page compiled: 20080306
site compiled:  Version GIF
(external) links checked: 20010223