Home
Topics
Computer Science
Microprocessors
parallel presence detect (PPD)

Definition

parallel presence detect (PPD)

Part of the Microprocessors glossary:

Also see PPD file (Postscript Printer Description file).

Parallel presence detect (PPD) is a method of using resistor s to communicate a memory module 's speed and density to the basic input/output system ( BIOS ) when a computer boots (starts or restarts). The BIOS uses this information to configure the memory modules to run correctly or to detect if an incorrect memory module has been installed. Today, serial presence detect ( SPD ) is used on newer memory modules because SPD can store up to 400 times more information than PPD. PPD is used with 30- and 72- pin SIMM s.

PPD indicates the memory module's specifications using parallel pins on the module that transmit a binary code. If a pin has a resistor connected to it, it's a logical zero. If a pin does not have a resistor connected to it, it's a logical one. The combination of resistors connected and not connected make up the binary code that the BIOS uses.

This was last updated in March 2011

Posted by: Margaret Rouse

Related Terms

Definitions

brownout reset
- A brownout reset is a circuit that causes a computer processor to reset (or reboot) in the event of a brownout, which is a significant drop in the power supply output voltage. (WhatIs.com)
Intel 4004
- The Intel 4004 was one of the first microprocessors ever produced, released in 1971. The 4004 was designed by Federico Faggin, Masatoshi Shima and others. (WhatIs.com)
octal latch
- An octal latch is an integrated circuit (IC) that contains eight binary digital circuits called latches. A latch is a form of sequential logic circuit. (WhatIs.com)

Glossaries

Microprocessors
- Terms related to microprocessors, including definitions about silicon chips and words and phrases about computer processors.
Hardware
- Terms related to computer hardware, including definitions about cables, connectors and power supply units and words and phrases about computing peripheral devices including the keyboard, mouse, au...
Internet applications
- This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Dig Deeper

People Who Read This Also Read...

Ask a Question. Find an Answer.Powered by ITKnowledgeExchange.com

Ask An IT Question

Get answers from your peers on your most technical challenges

Tech TalkComment

Share

Comments

Results

Contribute to the conversation

All fields are required. Comments will appear at the bottom of the article.

Back to top

More from Related TechTarget Sites

( View All TechTarget Sites )

CIO
Compliance
VMware
Storage
Security
IT Channel
Financial and HR Applications
Windows Server

CIO

( Find Out More About This Site )
- glocalization
  
  Glocalization is the concept that in a global market, a product or service is more likely to succeed when it is customized for the locality or culture in which it is sold.
- Vine (Vine app)
  
  Vine is a free mobile application that enables users to record and share an unlimited number of short, looping video clips with a maximum length of six seconds.
- Google Wallet
  
  Google Wallet is a mobile payment system developed by Google that allows smartphone users to store debit and credit card information for online and in-store purchases.
Compliance

( Find Out More About This Site )
- AICPA (American Institute of Certified Public Accountants)
  
  The AICPA (American Institute of Certified Public Accountants) is a member association for the accounting profession that sets ethical standards for accountants, as well as U.S. auditor standards for private companies, nonprofit organizations and the government.
- FTC (Federal Trade Commission)
  
  The FTC (Federal Trade Commission) is a U.S. federal regulatory agency designed to monitor and prevent anticompetitive, deceptive or unfair business practices.
- geolocation data
  
  Geolocation data is information associated with an electronic device that can be used to identify its physical location. The most common example of geolocation data is an IP address.
VMware

( Find Out More About This Site )
- vNUMA (virtual NUMA)
  
  vNUMA (virtual NUMA) is a memory-access optimization method for VMware virtual machines (VMs) that helps prevent memory-bandwidth bottlenecks.
- VMware host profile
  
  VMware Host Profiles is a vCenter Server tool to design and deploy ESX/ESXi hosts.
- VMware NSX
  
  VMware NSX is a virtual networking and security software product family created from VMware's vCloud Networking and Security (vCNS) and Nicira Network Virtualization Platform (NVP) intellectual property.
Storage

( Find Out More About This Site )
- storage hypervisor
  
  A storage hypervisor, also called software-defined storage, is a marketing term for software that allows storage to be controlled centrally in a storage pool regardless of what hardware the storage is located on.
- I/O contention (input/output contention)
  
  I/O contention (input/output contention), occurs when virtual machines compete for I/O resources because there is a limited storage bandwidth.
- erasure coding
  
  Erasure coding (EC) is a method of data protection in which data is broken into fragments, expanded and encoded with redundant data pieces, and stored across a set of different locations, such as disks, storage nodes or geographic locations.
Security

( Find Out More About This Site )
- computer forensics (cyber forensics)
  
  Computer forensics is the application of investigation and analysis techniques to gather and preserve evidence from a particular computing device in a way that is suitable for presentation in a court of law.
- multifactor authentication (MFA)
  
  Multifactor authentication (MFA) is a security system in which more than one form of authentication is implemented to verify the legitimacy of a transaction... (Continued)
- security information and event management (SIEM)
  
  Security information and event management (SIEM) is an approach to security management that seeks to provide a holistic view of organization’s information technology (IT) security.
IT Channel

( Find Out More About This Site )
- Apple Authorized Service Provider (Apple ASP)
  
  An Apple Authorized Service Provider (Apple ASP) is an individual or organization that can legally service Apple products although their warranties are held by other entities. Service by anyone other than an authorized service provider (ASP) will render a product's warranty void.
- authorized service provider (ASP)
  
  An authorized service provider (ASP) is an individual or an organization that is permitted to service products that are covered by warranties held by another entity. Service conducted by anyone other than an authorized service provider will generally render a warranty void.
- hosted services
  
  Hosted services are outsourced information technology (IT) systems and functions. A hosted service provider owns and oversees infrastructure, software and administrative tasks and makes the system available to clients, usually over the Internet.
Financial and HR Applications

( Find Out More About This Site )
- Automatic Data Processing Inc. (ADP)
  
  Automatic Data Processing Inc. (ADP) is a global business outsourcing services provider headquartered in Roseland, N.J.
- Kronos Inc.
  
  Kronos Inc. is a provider of workforce management software and associated services headquartered in Chelmsford, Mass.
- BPaaS (Business Process as a Service)
  
  Business Process as a Service (BPaaS) is a form of business process outsourcing (BPO) that employs a cloud computing service model.
Windows Server

( Find Out More About This Site )
- Microsoft FIM (Microsoft Forefront Identity Manager)
  
  Microsoft Forefront Identity Manager (FIM) is a self-service identity management software suite.
- Microsoft Software Assurance (SA)
  
  Microsoft Assurance Software is a program that was introduced in 2002 to help users with the maintenance of Microsoft Windows, Microsoft Office and applications for the server and desktop.
- DCPromo (Domain Controller Promoter)
  
  DCPromo (Domain Controller Promoter) is a tool in Active Directory that installs and removes Active Directory Domain Services and promotes domain controllers.

All Rights Reserved,Copyright 1999 - 2013, TechTarget