2 System Board

Chip-Set

PCI Bus Interface

Sequential PL-to-PCI memory write cycles are translated into PCI zero wait

 

state burst cycles. The maximum PCI burst transfer can be from 256 bytes to

 

4 KB. The chip supports advanced snooping for PCI master bursting, and

 

provides a pre-fetch mechanism dedicated for IDE read.

 

The PCI arbiter supports PCI bus arbitration for up to four masters using a

 

rotating priority mechanism. Its hidden arbitration scheme minimizes

 

arbitration overhead.

Data Path

Storage elements are provided for bidirectional data buffering among the 64-

 

bit PL data bus, the 64/32-bit memory data bus, and the 32-bit PCI address/

 

data bus.

 

There are three FIFO (first-in first-out) queues, and one read buffer for the

 

bridges of the PL, PCI, and Memory buses. This buffering is used, partly, to

 

smooth the differences in bandwidths between the three buses, thereby

 

improving the overall system performance. During bus operations between

 

the PL, PCI and Memory buses, the chip receives control signals from the

 

TXC, performs functions such as latching data, forwarding data to

 

destination bus, data assemble and disassemble.

 

Error correcting code (ECC) and parity bits are generated for memory

 

writes, and optional parity checking for memory reads. This operation

 

always sustains zero wait performance on PL-to-Memory, and always

 

streams zero wait performance on PCI-to-Memory and Memory-to-PCI.

 

Whilst accesses to the local memory are in progress, whether it be from the

 

PL or PCI bus, the TXC maintains control of the secondary cache, DRAMs,

 

and the datapath.

Level-2 Cache Memory

This unit controls the L2 cache memory, adopting a write back policy, in a

Controller

direct mapped organization. An 8-bit tag is used to allow the lowermost

 

64 MB of main memory to be cached (if more than 64 MB of main memory is

 

installed, accesses to the uppermost regions will be made directly to the main

 

memory modules, and not via the cache memory mechanism). When a

 

512 KB cache memory module is installed, the chip set allows provision for

 

an 11-bit tag to be used to allow 512 MB of main memory to be cached, but

 

this facility has not been enabled in the HP BIOS. More details on the use of

 

HP cache memory are given on page 32.

 

The cache memory line width is 32-bytes (256-bits), four times the width of

 

the Processor-Local data bus. Reads and writes always involve a full cache

 

line, and so require four back-to-back cycles on the bus. Since they involve

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HP Vectra VL 5/xxx 5 manual PCI Bus Interface, Data Path, Controller

Vectra VL 5/xxx 5 specifications

The HP Vectra VL 5/xxx was a series of desktop personal computers introduced by Hewlett-Packard in the mid-1990s. These machines were designed for both business and professional environments, making them suitable for a range of applications from basic office tasks to more demanding computing needs. This series played a significant role in HP's efforts to strengthen its market presence in the PC sector during a time when competition was intensifying.

One of the standout features of the HP Vectra VL 5/xxx line was its versatility. The series included various configurations designated by the '5/xxx' nomenclature, which indicated different performance levels and specifications. The performance was driven primarily by Intel Pentium processors, widely acclaimed for their reliability and efficiency. This allowed users to choose a model that suited their specific requirements, whether for everyday tasks or more resource-intensive applications.

In addition to its strong processing capabilities, the Vectra VL 5/xxx featured advanced graphics support, which was critical for visual applications and presentations. Many units in this series came equipped with onboard graphics capabilities that supported a range of resolutions, enhancing the user experience in both standard office environments and more creative settings.

Storage options were another highlight of the HP Vectra VL 5/xxx series. The machines typically featured a variety of hard drive configurations, allowing for ample data storage. Some models included the option for expanding storage through additional hard drives or external devices. Coupled with considerable RAM options, these machines ensured smooth multitasking and efficient performance across various applications.

Connectivity was also a core aspect of the Vectra VL 5/xxx. The systems typically included multiple USB ports, parallel and serial ports, and integrated networking capabilities. This made it easy for businesses to integrate the Vectra machines into their existing infrastructure, facilitating seamless interaction with peripherals and networks.

In terms of design, the HP Vectra VL 5/xxx series presented a robust yet compact form factor, which was ideal for office environments with limited space. Additionally, HP emphasized the reliability and serviceability of these machines, which included easy access to internal components for maintenance and upgrades, thereby extending the product life cycle.

Overall, the HP Vectra VL 5/xxx line offered a balanced combination of performance, flexibility, and reliability, making it a solid choice for organizations looking to leverage computing power for a range of professional applications. The series embodied HP's commitment to delivering quality and innovation in the ever-evolving landscape of personal computing.