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**82395SX     Smart Cache                                     12/17/90
***Notes:...
**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...
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*Headland/G2...
**HT44          Secondary Cache                                c:Jun92
***Info:
The  HT44 is  a  look-aside write-through,  80486SX,  486DX or  486DX2
secondary cache  controller. It is  packaged in an  inexpensive 84-pin
plastic-leaded chip carrier (PLCC).

Architecture
With  its look-aside architecture,  the HT44  fits beside  the CPU-to-
Memory bus  and not in  the data path.   Therefore, once the  HT44 has
been designed  into a  486 system, it  can be populated  for secondary
cache systems or left vacant for non-secondary cache systems. The HT44
is direct-mapped to the available address space.

Performance
The  HT44  has a  number  of  performance  enhancing features.   These
include zero-waitstate burst line fills  to the 486 on secondary cache
hits, and simultaneous 486 and secondary cache updates on read misses.

Memory Configurations
The HT44 supports  cache sizes from 32KBytes to  1MB. Both synchronous
and asynchronous  SRAMs are supported.  25ns SRAMs are  sufficient for
zero-wait-state operation at 33MHz.

Chip Set Support
The HT44 can,  be implemented with minimal glue logic  in a 486 system
with the  HTK340 (code  name Shasta) chip  set.  The registers  in the
HTK340  allow  for programming  of  non-cacheable and  write-protected
areas of  memory. The  HTK340 will support  the HT44  with synchronous
SRAMs only.   Future Headland chip sets will  support both synchronous
and asynchronous SRAM designs.

The HT44  can also be used  with some third-party  chip sets, however,
additional glue logic may be required.

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**82C895         System/Power Management Controller (cached)   c:Sep94
***Notes:...
***Info:...
***Configurations:...
***Features:
o   Processor interface:
    - Intel 80486SX, DX, DX2, SLe, DX4, P24T, P24D 
    - AMD 486DX, DX2, DXL, DXL2, Plus
    - Cyrix DX, DX2, M7
    - CPU frequencies supported 20, 25, 33, 40 and 50MHz
o   Cache interface:
    - Direct Mapped Cache
    - Two banks interleaved or single bank non-interleaved
    - 64, 128, 256 and 512K cache sizes
    - Programmable wait states for L2 cache reads and writes
    - 2-1-1-1 read burst and zero wait state write @ 33MHz
    - No Valid bit required
    - Supports CPUs with L1 write-back support
o   DRAM interface:
    - Up to 128MB main memory support
    - Supports 256KB, 1MB, 4MB, and 16MB single- and double-sided SIMM 
      modules
    - Read page-hit timing of 3-2-2-2 at 33MHz
    - Supports hidden, slow and CAS-before-RAS refresh
    - Four RAS lines to support four banks of DRAM
    - Programmable wait states for DRAM reads and writes
    - Enhanced DRAM configuration map
o   Power management:
    - Support for SMM (System Management Mode) for system power 
      management implementations
    - Programmable power management
    - Programmable wake-up events through hardware, software and 
      external SMI source
    - Multiple level GREEN support (NESTED_GREEN)
    - STPCLK# protocol support
    - One programmable GREEN event timer
o   ISA interface:
    - 100% IBM PC/AT ISA compatible
    - Integrates DMA, timer and interrupt controllers
    - Optional PS/2 style IRQ1 and 12 latching
o   VESA VL interface:
    - Conforms to the VESA v2.0 specification
    - Optional support for up to two VL masters
o   Miscellaneous features:
    - Full support for shadow RAM, write protection, L1/L2 
      cacheability for video, adapter and system BIOS
    - Enhanced arbitration scheme
    - Transparent 8042 emulation for fast CPU reset and GATEA20 
      generation
o   Packaging:
    - Higher integration
    - Reduced TTL count
    - Low-power, high-speed 0.8-micron CMOS technology
    - 208-pin PQFP (Plastic Quad Flat Pack)

**82C898         System/Power Management Controller (non-cache)c:Nov94...
**
**Support Chips:
**82C601/2       Buffer Devices                                 <Nov94...
**82C822         PCIB (VLB-to-PCI bridge)                         c:94...
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