computer science

PIIX

PIIX is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand PIIX rather than just read about it. In short: PCI IDE ISA Xcelerator (PIIX), also known as Intel 82371, is a family of Intel southbridge microchips employed in some Intel chipsets. x86 virtualization implementations often support emulations of various PIIX-based chipsets. Versions PIIX The PIIX integrated an IDE controller with two 8237 DMA controllers, the 8254 PIT, and two 8259 PICs and a PCI to ISA bus bridge.

Key takeaways

PIIX belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect PIIX to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PIIX from memory before moving on to harder problems.

Reference excerpt

PCI IDE ISA Xcelerator (PIIX), also known as Intel 82371, is a family of Intel southbridge microchips employed in some Intel chipsets. x86 virtualization implementations often support emulations of various PIIX-based chipsets.

Versions

PIIX The PIIX integrated an IDE controller with two 8237 DMA controllers, the 8254 PIT, and two 8259 PICs and a PCI to ISA bus bridge. It was introduced with the 430FX Triton chipset in 1995. The mobile version was introduced with the 430MX mobile Triton chipset. The following variations existed:

82371FB (PIIX) 82371MX (MPIIX) Mobile

PIIX3 The PIIX3 introduced a USB 1.0 controller and support for an external I/O APIC. It was used with the 430HX and 430VX Triton II and 440FX northbridges. The following variations existed:

82371SB (PIIX3)

Gallery

PIIX4

The PIIX4 introduced ACPI support, an improved IDE controller with Ultra DMA/33 support, and an integrated MC146818 style RTC and CMOS controller. It was used with the 430TX and the 440LX Balboa northbridges. The PIIX4E updated the ACPI support. It was mainly used in 440BX and 440GX chipsets but 440EX, 440ZX, and 450NX chipsets also employed it. The mobile version was used in 440BX and 440ZX-M chipsets. The following variations existed:

82371AB (PIIX4) Base 82371EB (PIIX4E) Enhanced 82371MB (PIIX4M) Mobile

PIIX5 This seems to be a reference to the Itanium 460GX I/O and Firmware Bridge (IFB) chipset component which has been referred to as 82372FB (PIIX5), 82468FB, and finally FW82468GX (IFB).

See also List of Intel chipsets Platform Controller Hub (PCH) System Controller Hub (SCH) I/O Controller Hub (ICH) Super I/O Northbridge (computing) Southbridge (computing)

References

Bibliography 82371FB (PIIX) and 82371SB (PIIX3) PCI ISA IDE Xcelerator, archived from the original on 2017-04-03 Intel(R) 82371SB (PIIX3) PCIset Specification Update, archived from the original on 2017-01-25 Intel(R) 82371AB PCI-TO-ISA/IDE Xcelerator (PIIX4) Datasheet (PDF), archived from the original on 2021-07-25 Intel 82371AB PIIX4, Intel 82371EB PIIX4E and Intel 82371MB PIIX4M Specification Update (PDF), archived from the original on 2021-04-29

Illustrations

Worked examples

Example 1 — a first encounter with PIIX

Start with the simplest possible case. Write down what PIIX claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to PIIX before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about PIIX ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of PIIX

In research: PIIX appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses PIIX in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: PIIX is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computer hardware stubs, Intel chipsets, Intel products, so understanding it makes those chapters shorter.
In everyday life: Look for PIIX outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study PIIX in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PIIX means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain PIIX out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PIIX in simple terms?

Why does PIIX matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study PIIX?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on PIIX.