[Home] [This version is outdated, a new version is here]
*Title...
*Search:...
*Read Me/FAQ/General Info...
*_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...
**82495DX/490DX DX CPU-Cache Chip Set <Sep91
***Notes:...
***Info:
The 50 MHz Intel486 DX CPU-Cache Chip Set provides a high performance
solution for servers and high-end desktop systems. This binary
compatible solution has been optimized to provide 50 MHz, zero wait
state performance. The CPU-Cache chip set combines the 50 MHz Intel486
Microprocessor with the 82495DX/82490DX cache subsystem. It delivers
integer performance of 41 V1.1 Dhrystone MlPs and a SPEC integer
rating of 27.9. The cache subsystem features the 82495DX Cache
Controller and the 82490DX Dual Ported Data RAM. Dual ported buffers
and registers of the 82490DX allow the 82495DX Cache Controller to
concurrently handle CPU bus, memory bus, and internal cache operations
for maximum performance.
The CPU-Cache Chip Set offers many features that are ideal for multi-
processor based systems. The Write-Back feature provides efficient
memory bus utilization by reducing bus traffic through eliminating
unnecessary writes to main memory. The CPU-Cache chip set also
supports MESI protocol and monitors the memory bus to guarantee cache
coherency.
The 50 MHz Intel486 DX CPU and 82495DX/82490DX Cache subsystem are
produced on Intel's latest CHMOS V process which features submicron
technology and triple layer metal.
3.0 ARCHITECTURAL OVERVIEW
3.1 Introduction
The Intel486 CPU-cache chip set provides a tightly coupled processing
engine based on the Intel486 microprocessor and a cache subsystem
comprised of the 82495DX cache controller and multiple 82490DX cache
components. Figure 3.1 [see datasheet] diagrams the basic config-
uration.
The cache subsystem provides a gateway between the CPU and the memory
bus. All CPU accesses that can be serviced locally are transparent to
the memory bus and serve to avoid bus traffic. As a result, the cache
chip set reduces memory bus bandwidth to both increase Intel486
processor performance and support efficient multiprocessor systems.
The cache subsystem also decouples the CPU from the memory bus to
provide zero-wait-state operation at high clock frequencies while
allowing relatively slow and inexpensive memories.
The CPU-cache chip set prevents latency and bandwidth bottlenecks
across a variety of uniprocessor and multiprocessor designs. The
processor’s on-chip cache supports a very wide CPU data bus and
high-speed data movement. The second-level cache greatly extends the
capabilities of the on-chip cache resources, enabling a larger portion
of memory cycles to be satisfied independently of the memory bus.
3.2 CPU-Cache Chip Set Description
The chip set is comprised of three functional blocks:
3.2.1 CPU
The chip set includes a special version of the Intel486DX micropro-
cessor at 50 MHz. The Intel486DX Microprocessor Data Sheet provides
complete component specifications.
3.2.2 CACHE CONTROLLER
The 82495DX cache controller is the main control element for the chip
set. providing tags and line states. and determining cache hits and
misses. The 82495DX executes all CPU bus requests and coordinates all
main memory accesses with the memory bus controller (MBC).
The 82495DX controls the data paths of the 82490DX cache components
for cache hits and misses and furnishes the CPU with needed data. The
controller dynamically adds wait states as needed using the most
recently used (MRU) prediction algorithm.
The 82495DX also performs memory bus snoop operations in shared memory
systems and drives the cycle address and other attributes during
memory bus accesses. Figure 3.2 [see datasheet] diagrams the 82495DX.
3.2.3 CACHE SRAM
Multiple 82490DX cache components provide the cache SRAM and data
path. Each component includes the latches, muxes and logic needed to
work in lock step with the 82495DX to efficiently serve both hit and
miss accesses. The 82490DX components take full advantage of VLSI
silicon flexibility to exceed the capabilities of discrete
implementations. The 82490DX components support zero-wait-state hit
accesses and concurrent CPU and memory bus accesses, and they
replicate MRU bits for autonomous way prediction. During memory bus
cycles. the 82490DX components act as a gateway between CPU and memory
buses. Figure 3.3 [see datasheet] diagrams an 82490DX cache component.
3.3 Secondary Cache Features
The 82495DX cache controller and 82490DX cache components provide a
unified, software transparent secondary data and instruction cache.
The cache enables a highspeed processor core that provides efficient
performance even when paired with a significantly slower memory bus.
The secondary cache interprets CPU bus cycles and can service most
memory read and write cycles without accessing main memory. I/O and
other special cycles are passed directly to the memory bus. The cache
has a dual-port structure that permits concurrent CPU and memory bus
operation.
The 82495DX cache controller contains the 8K tag entries and logic
needed to support a cache as large as 256K. Combinations of between 4
and 9 82490DX cache SRAMs are used to create caches ranging from 128K
to 256K, with or without data parity.
The MBC provides logic needed to interface the CPU, 82495DX and
82490DX to the memory bus. Because the MBC also affects system
performance. its design can be the basis of product differentiation.
***Configurations:...
***Features:...
**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...
**GC101/102 12/16MHz PC/AT Compatible Chip Set c:Feb88
***Info:...
***Configurations:...
***Features:...
**GC101/102/103 12/16MHz PC/AT Compatible Chip Set + EMS 4.0 c:Jul89...
**GCK113 80386 AT Compatible Chip Set c:oct89...
**GCK181 Universal PS/2 Chip Set c:Mar89...
**HT11 Single 286 AT Chip [no datasheet] <Aug90...
**HT12/+/A Single 286 AT Chip with EMS support c:Aug90...
**HT18 80386SX Single Chip c:Sep91
***Info:...
***Configurations:...
***Features:...
**HT21 386SX/286 Single Chip (20 MHz) c:Aug91...
**HT22 386SX/286 Single Chip (25 MHz) c:Sep91...
**HT25 3-volt Core Logic for 386SX c:Dec92...
**HT35 Single-Chip Peripheral Controller [partial info] ?...
**HTK320 386DX Chip Set c:Sep91...
**HTK340 "Shasta" 486 Chip Set c:Jun92...
**Support Chips:
**HT44 Secondary Cache c:Jun92...
**Other:...
*HMC (Hulon Microelectronics)...
*Logicstar...
*Motorola...
*OPTi...
*PC CHIPS/Amptron/Atrend/ECS/Elpina/etc...
*SIS...
*Symphony...
*TI (Texas Instruments)...
*UMC...
*Unresearched:...
*VIA...
*VLSI...
**VL82CPCAT-QC AT 12 MHz 0/1 ws c88
***Basics:...
***Info:...
***Configurations:...
***Features:...
**VL82CPCPM-QC AT 16 MHz 0/1 ws [no datasheet] c88...
**VL82CPCAT-16QC/-20QC AT 16 MHz or 20 MHz, 0/1 ws +386SX c89...
**VL82CPCPM-16QC/-20QC AT 16 MHz or 20 MHz, Page-Mode +386SX c89...
**VL82C031/032/033 PS/2 Model 30-compatible chip set c88...
**VL82C286-SET TOPCAT 286/386SX PC/AT-Compatible Chip Set ?...
**VL82C386-SET TOPCAT 386DX PC/AT-Compatible Chip Set ?...
**VL82C386sx-SET TOPCAT 286/386SX PC/AT-Compatible Chip Set ?...
**VL82C310 SCAMP-LT ?...
**VL82C311 SCAMP-DT ?...
**VL82C311L SCAMP-DT 286 ?...
**VL82C312 SCAMP Power Management Unit (PMU) ?...
**VL82C315A SCAMP II, Low-Power Notebook Chipset ?...
**VL82C322A SCAMP II, Power Management Unit (PMU) ?...
**VL82C316 SCAMP II, PC/AT-Compatible System Controller ?...
**VL82C323 SCAMP II, 5 Volt Power Management Unit (PMU) ?...
**VL82C380 Single chip 386DX PC/AT Controller +on-chip cache ?...
**VL82C325 VL82C386SX System Cache controller ?...
**VL82C335 VL82C386DX System Cache ctrl. [no d.sheet] ?...
**VL82C315A/322A/3216 Kodiak 32-Bit Low-Voltage Chip Set ?...
**VL82C420/144/146 SCAMP IV [no datasheet, some info] c93...
**VL82C480 System/Cache/ISA bus Controller ?...
**VL82C481 System/Cache/ISA bus Controller c92...
**VL82C486 Single-Chip 486, SC486, Controller ?...
**VL82C425 486 Cache controller ?...
**???????? Cheetah 486, PCI [no datasheet] ?...
**VL82C3216 Bus Expanding Controller Cache with write buffer ?...
**VL82C521/522 Lynx/M ?...
**VL82C530 Eagle Ð c95...
**VL82C541/543 Lynx c95...
**VL82C591/593 SuperCore 590 c94...
**VL82C594/596/597 Wildcat c95...
**I/O Chips:
**VL82C106 Combination I/O chip ?...
**VL82C107 SCAMP Combination I/O chip ?...
**VL82C108 TOPCAT Combination I/O chip ?...
**VL82C110 Combination I/O chip ?...
**VL82C113 SCAMP Combination I/O chip ?...
**VL82C114 Combination I/O chip ?...
**Video: ...
**Disk:...
**Modems:...
**Other:...
**Not sure if they actually exist...
*Western Digital...
*Winbond...
*ZyMOS...
*General Sources:...
(c) Copyright mR_Slugs Warehouse - All rights Reserved