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**Why this document is not GPL or a wiki
The document is copyright, it is NOT GPL'ed text. While the GPL is a
fantastic idea, I have chosen not to make this freely copied and
modified. The reasons are as follows:
1. GPL text tends to be copied...EVERYWHERE. For example, if you look
up a subject on wikipedia, then try to get more information, or a
different perspective on say about.com. There you find the EXACT
SAME TEXT. This is what mirrors are for. It's an unintended
consequence, but it can lead to misinformation being spread
everywhere. A bigger problem.
2. There seems to be fewer and fewer informative websites. It used to
be that if you searched for something you would find a website
about a particular subject. Now you tend to find the encyclopedia
and often nothing else (well quickly).
In addition the majority of this text is quotes.
The wiki concept is a good idea, but they have problems. Because no
one "owns" the work they seem to go to two extremes. Either no one
maintains them, or there are edit wars. Also anyone can edit them.
**Definition of a chip set:...
**'chip set', 'chip-set' or 'chipset'?...
**What's not included:...
**Who made the first chip set?...
**Spelling errors/mistyped words...
**Info needed on:...
**A note on VESA support of 486 chipsets....
**Datasheets:...
*_IBM...
*ACC Micro...
*ALD...
*ALi...
*AMD . . . . . . . [no datasheets, some info]...
*Chips & Technologies...
*Contaq . . . . . [no datasheets, some info]...
*Efar Microsystems [no datasheets, some info]...
*ETEQ...
*Faraday...
*Forex . . . . . . [List only, no datasheets found]...
*Intel...
**82385 32-bit Cache Controller for 80386 09/29/87
***Notes:...
***Info:
The 82385 Cache Controller is a high performance 32-bit peripheral for
Intel's 80386 Microprocessor. It stores a copy of frequently accessed
code and data from main memory in a zero wait state local cache
memory. The 82385 enables the 80386 to run at its full potential by
reducing the average number of CPU wait states to nearly zero. The
dual bus architecture of the 82385 allows other masters to access
system resources while the 80386 operates locally out of its cache.
In this situation, the 82385's "bus watching" mechanism preserves
cache coherency by monitoring the system bus address lines at no cost
to system or local throughput.
The 82385 is completely software transparent, protecting the integrity
of system software. High performance and board savings are achieved
because the 82385 integrates a cache directory and all cache
management logic on one chip.
1.0 82385 FUNCTIONAL OVERVIEW
Th~ 82385 Cache Controller is a high performance 32-bit peripheral for
Intel's 80386 microprocessor. This chapter provides an overview of
the 82385, and of the basic architecture and operation of an 80386/
82385 system.
1.1 82385 OVERVIEW
The main function of a cache memory system is to provide fast local
storage for frequently accessed code and data. The cache system
intercepts 80386 memory references to see if the required data resides
in the cache. If the data resides in the cache (a hit), it is returned
to the 80386 without incurring wait states. If the data is not cached
(a miss), the reference is forwarded to the system and the data
retrieved from main memory. An efficient cache will yield a high "hit
rate" (the ratio of cache hits to total 80386 accesses), such that the
majority of accesses are serviced with zero wait states. The net
effect is that the wait states incurred in a relatively infrequent
miss are averaged over a large number of accesses, resulting in an
average of nearly zero wait states per access. Since cache hits are
serviced locally, a processor operating out of its local cache has a
much lower "bus utilization" which reduces system bus bandwidth
requirements, making more bandwidth available to other bus masters.
The 82385 Cache Controller integrates a cache directory and all cache
management logic required to support an external 32 Kbyte cache. The
cache directory structure is such that the entire physical address
range of the 80386 (4 Gigabytes) is mapped into the cache. Provision
is made to allow areas of memory to be set aside a non-cacheable. The
user has two cache organization options: direct mapped and 2-way set
associative. Both provide the high hit rates necessary to make a
large, relatively slow main memory array look like a fast, zero wait
state memory to the 80386.
A good hit rate is an essential ingredient of a successful cache
implementation. Hit rate is the measure ,of how efficient a cache is
in maintaining a copy of the most frequently requested code and data.
However, efficiency is not the only factor for performance
consideration. Just as essential are sound cache management
policies. These policies refer to the handling of 80386 writes,
preservation of cache coherency, and ease of system design. The
82385's "posted write" capability allows 80386 memory writes,
including non-cacheable, to run with zero wait states, and the 82385's
"bus watching" mechanism preserves cache coherency with no impact on
system performance. Physically, the 82385 ties directly to the 80386
with virtually no external logic.
***Versions:...
***Features:...
**82385SX 32-bit Cache Controller for 80386SX 01/25/89...
**82395DX High Performance Smart Cache 06/18/90...
**82395SX Smart Cache 12/17/90...
**82396SX Smart Cache 12/17/90...
**82485 Turbo Cache (and 485Turbocache) c90...
**82489DX Advanced Programmable Interrupt Controller 10/12/92...
**82495DX/490DX DX CPU-Cache Chip Set <Sep91...
**82495XP/490XP Cache Controller / Cache RAM (for i860) 06/05/91...
**82496/491 Cache Controller / Cache RAM (for P5 Pentium) 03/22/93...
**82497/492 Cache Controller / Cache RAM (for P54 Pentium) <Nov94...
**82498/493 Cache Controller / Cache RAM (for P54 Pentium) <Nov94...
**
**Later chipsets (basic spec):
**440 series:...
**450NX (?) 06/29/98:...
**????? (Profusion) c:99...
**800 series...
*Headland/G2...
*HMC (Hulon Microelectronics)...
*Logicstar...
*Motorola...
*OPTi...
**82C683 386/486AWB EISA [no datasheet] ?
***Notes:...
**82C693/6/7 Pentium uP Write Back Cache EISA c:93...
**82C700 FireStar c:97...
**82C701 FireStar Plus c:97...
**82C750 Vendetta [no datasheet] ?...
**82c801 SCWB2 DX Single Chip Solution c:92...
**82C802 SCWB2 PC/AT Single Chip [no datasheet] ?...
**82C802G/GP System/Power Management Controller (cached) c:93...
**82C895 System/Power Management Controller (cached) c:Sep94...
**82C898 System/Power Management Controller (non-cache)c:Nov94...
**
**Support Chips:
**82C601/2 Buffer Devices <Nov94...
**82C822 PCIB (VLB-to-PCI bridge) c:94...
**Other:...
*PC CHIPS/Amptron/Atrend/ECS/Elpina/etc...
*SIS...
*Symphony...
*TI (Texas Instruments)...
*UMC...
*Unresearched:...
*VIA...
**SL9095 Power Management Unit ?
***Info:...
***Versions:...
***Features:...
**SL9151 80286 Page Interleave Memory Controller (16-25MHz) ?...
**SL9250 80386SX Page Mode Memory Controller (16/20MHz 8MB) ?
***Info:...
***Versions:...
***Features:...
**SL9251 80386SX Page Interleave Memory Controller <04/13/90...
**SL9252 80386SX System and Memory Controller <06/12/90...
**SL9350 80386DX Page Mode Memory Controller (16-25MHz 16MB) ?...
**SL9351 80386DX Page Interleave Memory Controller (33MHz) ?...
**SL9352 80386DX System and Memory Controller <06/12/90...
**SLXXXX Other chips...
**
**VT82C470 "Jupiter", Chip Set (w/o cache) 386 [no datasheet] ?
**VT82C475 "Jupiter", Chip Set (w/cache) 386 [no datasheet] ?
**VT82C486/2/3 "GMC chipset" [no datasheet, some info] ?...
**VT82C495/480 "Venus" Chip Set [no datasheet] ?
**VT82C495/491 ? EISA Chip Set [no datasheet, some info] <93...
**VT82C496G Pluto, Green PC 80486 PCI/VL/ISA System <05/30/94...
**VT82C530MV 3.3V Pentium chipset [no datasheet, some info]<05/30/94...
**VT82C570M Apollo Master, Green Pentium/P54C <06/22/95...
**VT82C580VP Apollo VP, Pentium/M1/K5 PCI/ISA System <02/15/96...
**VT82C580VPX Apollo VPX, VPX/97, Pentium with 66/75MHz Bus <01/09/97...
**VT82C590 Apollo VP2, VP2/97, Single-Chip Pentium 66MHz <01/10/97...
**VT82C597/AT Apollo VP3, Single-Chip for Pentium with AGP <10/03/97...
**VT82C598MVP Apollo MVP3,Single-Chip 66/75/83/100MHz & AGP <09/22/97...
**VT8501 Apollo MVP4,Single-Chip 66-100MHz & AGP <11/04/98...
**VT82C680 Apollo P6, Pentium-Pro Chip Set <08/30/96...
**Support chips:
**VT82C505 Pentium/486 VL to PCI Bridge <05/30/94...
**VT82C586/A/B PCI Integrated Peripheral Controller <10/13/96...
**VT82C596/A Mobile PCI Integrated Peripheral Controller <11/05/97...
**VT82C686A/B PCI Super-I/O Integrated Peripheral Ctrl. <02/10/98...
**Later P-Pro/II/III/Celeron...
**Later AMD...
**Other...
*VLSI...
*Western Digital...
*Winbond...
*ZyMOS...
*General Sources:...
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