User`s guide

1.1 System Components and Features
most cases. The Bcache size can be reconfigured through onboard hardware
jumpers. As implemented in the EB164, the Bcache operates in 64-byte mode
only.
1.1.4 PCI Interface Overview
The EB164 PCI interface is the main I/O bus for the majority of functions
(SCSI interface, graphics accelerator, and so on). The PCI interface provides a
selectable PCI speed between 25 MHz and 33 MHz (based on the 21164 clock
divisor). An onboard PCI-to-ISA bridge is provided through an Intel 82378ZB
Saturn-I/O chip (SIO).
The PCI bus has three dedicated PCI expansion slots (one 64-bit and two
32-bit) and one shared 64-bit PCI/ISA slot.
1.1.5 ISA Interface Overview
The ISA bus has two dedicated slots and a third shared ISA/PCI slot. It
provides the following system support functions:
• Mouse and keyboard controller functions—provided by an Intel 8242 chip.
• An IDE interface, a diskette controller, two universal asynchronous
receiver–transmitters (UARTs) with full modem control, and a bidirectional
parallel port—provided by a National 87312 combination chip.
• A time-of-year (TOY) function—provided by a Dallas Semiconductor
DS1287 chip.
• Operating system support—provided by a 1MB flash ROM that contains
firmware and debug monitor code.
Users can develop code on a host system, and load software into the EB164
through a serial line, diskette, or Ethernet board. In addition, sectors of
the flash ROM can be programmed for application-specific purposes.
1.1.6 Miscellaneous Logic
The EB164 contains the following miscellaneous components:
• Clocks
A 26.66-MHz oscillator and phase-locked loop (PLL) clock generator provide
a clock source to the 21164 microprocessor and system.
A 14.3-MHz crystal and frequency generator provide a clock source for ISA
devices.
• Serial ROM
1–4 Introduction to the EB164