Pci And Sub-Isa Bus Interface - Micros Systems Workstation 4 LX Service Manual

WS4 Technical Overview

PCI and Sub-ISA Bus Interface

PCI and Sub-ISA Bus Interface

REF: AB28/ABRD36 - (Sheets 2, 5, 6 and 10)
Figure 2-5 shows a block diagram of the SC3200 PCI and Sub-ISA Bus as
implemented on the original Workstation 4 System Boards.
In order to reduce the number of pins on the SC3200 device, the PCI and Sub-ISA bus
pins are shared. Sharing occurs on a bus-cycle by bus-cycle basis, where the Core
Logic PCI bridge arbitrates between PCI and Sub-ISA cycles.
PCI Bus Interface Feature Summary
• PCI 2.1 with wake-up capability
• 32-bit data path, up to 33Mhz
• +3.3V signal support only
• Glue-less interface for an external PCI device
• Fixed priority of PCI devices.
2-8
Figure 2-5: SC3200 PCI/Sub-ISA Bus Interface
Workstation 4 and 4 LX Field Service Guide