Compaq 164SX - Manual (Page 18)

1–4 Introduction
System Components and Features
1.1.3 L2 Bcache Subsystem Overview
The AlphaPC 164SX board-level L2 backup cache (Bcache) is a 1MB, direct-
mapped, synchronous, pipelined burst SROM with a 128-bit data path. The board is
capable of handling an L2 cache size of 2MB. See Section 2.3 for more information
about the Bcache.
1.1.4 PCI Interface Overview
The AlphaPC 164SX PCI interface, with a 33-MHz data transfer rate, is the main
I/O bus for the majority of functions (SCSI interface, graphics accelerator, and so
on). PCI-EIDE support is provided by an onboard controller chip (Cypress
CY82C693U-NC), which also provides a PCI-to-ISA bridge, a mouse and keyboard
controller, and a time-of-year (TOY) clock.
The PCI bus has four dedicated PCI expansion slots (two 64-bit and two 32-bit).
1.1.5 ISA Interface Overview
The ISA bus provides the following system support functions:
• Two expansion slots.
• An SMC FDC37C669 combination controller chip that provides:
– A diskette controller
– Two universal asynchronous receiver-transmitters (UARTs) with full
modem control
– A bidirectional parallel port
1
64-bit-wide DIMMs can also be used.
Bank 0 1 Bank 1 1
Total Memory J7 J8 J9 J10
192MB 8Mb × 72 8Mb × 72 4Mb × 72 4Mb × 72
256MB 8Mb × 72 8Mb × 72 8Mb × 72 8Mb × 72
16Mb × 72 16Mb × 72 — —
512MB 16Mb × 72 16Mb × 72 16Mb × 72 16Mb × 72
Table 1–1 AlphaPC 164SX SDRAM Memory Configurations (Sheet 2 of 2)