[Home] [This version is outdated, a new version is here]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...
**82485 Turbo Cache (and 485Turbocache) c90
***Notes:...
***Info:
The 82485 is a second-level cache controller designed to improve the
performance of Intel486 Microprocessor systems. One 82485 cache
controller supports 64K or 128K bytes of second level cache memory
that maps to the entire 4 Gigabytes of the Intel486 microprocessor
address space. The controller is completely software transparent. One
controller plus SRAMs provides a 64K or a 128K cache. External EPROM
can be cached yet remain write protected. The 82485 is fully
compatible with the Intel486 microprocessor. All Intel486 CPU bus
cycles and timings are supported.
A complete, optional second level cache controller using the 82485 is
available as the 485Turbocache Module from Intel (data sheet order
number 240722).
2.0 FUNCTIONAL DESCRIPTION
2.1 Introduction
The 82485 is a single ported, two-way set associative cache controller
designed specifically to interface with the Intel486 microprocessor.
The controller supports either a sectored configuration (two lines per
tag) or a non-sectored configuration (one line per tag). The 82485
will directly support a nonsectored 64K data cache or a 128K sectored
data cache. Both the 64K and 128K configurations are able to map the
entire 4 gigabytes of the Intel486 microprocessor address space. The
82485 interfaces directly to the Intel486 microprocessor. All Intel-
486 CPU bus cycles and timings are supported. The 82485 also supports
0 wait state processor operation when there is a cache hit and has
provisions to support invalidation cycles, BOFF# cycles, and premature
BLAST# terminations. The controller is look aside (monitors bus act-
ivity in parallel to the processor) and write through (all writes pro-
pagate to the system bus), so it supports the same cache consistency
mechanisms as the Intel486 CPU. The controller also provides a safe
method to cache ROM BIOS through the use of a write protect pin and a
write protect strapping option.
The data cache (Static RAM) resides external to the 82485. The 82485
provides all controls for the SRAMs. No external latches or tran-
ceivers are required. The 82485 output buffers support up to eight
SRAMs. A 64K cache can be designed with only five components; nine
components for a 128K cache. Two-way set associativity is provided by
dual banked SRAMs. Data parity is supported.
The 82485 can be used to design a custom second level cache
configuration. For an easier system design and higher integration, the
82485M Turbocache can be used (see data sheet order number 240722).
This module is a complete second level cache in one package. It
consists of a single 82485 cache controller and SRAM to provide a
complete 64K or 128K second level Intel486 microprocessor second level
cache.
***Versions:...
***Features:...
**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...
*PC CHIPS/Amptron/Atrend/ECS/Elpina/etc...
*SIS...
*Symphony...
**SL82C465 Cache Controller (for 486/386DX/SX) c:91
***Info:
The SL82C465 cache controller supports both 1X and 2X clock modes. The
1X clock mode means that the CCLK2 signal is used as the CPU clock;
the 2X clock mode means that the PCLK signal (half the frequency and
the phase indicator of CCLK2) is used as the CPU clock. The SL82C465
and other CPU local bus devices run at the same clock frequency as the
CPU, while the rest of the system runs at the frequency of PCLK. In
other words, the operating frequency of the system logic is either the
same (2X clock mode) or half the speed of the CPU (1X clock mode). For
the 1X clock mode, the timing of the signals between the CPU/Cache and
the system logic interface is converted by the SL82C465 automatically
to satisfy the requirement of individual clocks. Table 1-1 [see
datasheet] lists the operating frequencies of the CPU local bus and
the system logic with the oscillator used.
The 2X clock mode is recommended for a CPU frequency no faster than
33Mhz because the system logic is available at the targeted speed and
the performance is slightly better than if 1X clock mode were
used. For a CPU frequency faster than 33Mhz, the 1X clock mode is
preferred for 486 systems because it becomes increasingly more
difficult to build a reliable system with an oscillator faster than
66Mhz.
***Versions:...
***Features:...
*TI (Texas Instruments)...
*UMC...
*Unresearched:...
*VIA...
**VT82C597/AT Apollo VP3, Single-Chip for Pentium with AGP <10/03/97
***Info:...
***Configurations:...
***Features:...
**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:...
(c) Copyright mR_Slugs Warehouse - All rights Reserved