bus,

the

 

cache memory enters “snoop” mode and monitors all write

 

 

and

 

read

 

operations. If memory data is written

 

to

a

 

location

in

the

cache and the cache line is in

the “modified” state, the corresponding

cache line

is

written

 

back

to system

memory

 

and

invalidated.

 

 

 

When

the

 

microprocessor

performs

a

memory

read,

 

the

data

address

 

is

used

to find the data in the

cache. If

the

data is found (a hit), it is

read

from

the

cache

 

memory

and

no

external

 

bus

cycle

occurs. If

 

the

 

data

 

is

not

found

(a

miss),

an

 

external

bus

cycle is used to read

the

 

data

 

from

system

 

memory. If

the

address

of

the

missed

data

is

in

cacheable

address

 

space,

the data is

stored

in

the

cache

memory

and

 

the

remainder

of

 

the

cache

line

is

read.

 

 

 

 

 

 

 

 

 

When the microprocessor performs a memory write, the data

 

 

 

address

is

used

to

search

the

cache. If

 

the

address

is

found

(a hit),

the

 

data

 

is written to the cache

and

no

external

bus cycle is used to

write the data to system memory. (If the address of the write

 

operation

was not in the cache

memory but was in cacheable

 

 

 

address

space,

the

data

is

read

back

into

the

cache

memory and

the

remainder

of

the

cache line

is

read.)

 

 

 

 

 

 

 

 

 

 

 

 

Cacheable

Address

Space

 

 

 

 

 

 

 

 

 

 

 

 

Cacheable

address

space

is

defined

as

system

memory

that

resides

on the system board (0–640

KB and 1 MB–256 MB). Cacheability of

system

memory

is

up

to 64 MB for

Pentium

or 512 MB for Pentium II

in the L2 cache. Nothing in

address

range

hex A0000–BFFFF,

I/O

 

address

space,

or

memory

in

any

AT

slot

is

cached.

 

 

ROM address space (hex C0000–C9FFF and F0000–FFFFF) is L1

 

 

cacheable codefor read operations. Ifonlydata in this address

 

range

is

already

in

cache

memory

and the

address range is

written

to,

the

cached

line

is

invalidated

and

is

read

again

from

RAM, where

the

BIOS

is

shadowed.

 

 

 

 

 

 

 

 

 

Bus Adapter

When the computer is attached to the ThinkPad SelectaDock III docking system, the PCI adapters or AT-bus adapters can be used through the docking system.

System Board 2-3

Page 24 Page 26
Page 25
Image 25
IBM 600 manual Bus Adapter, Invalidated When Microprocessor Performs, Address Space, Shadowed
Page 24 Page 26

600 specifications

The IBM 600 series is a notable line of enterprise-level servers that has garnered attention for its robust performance, advanced features, and scalability suitable for large organizations. Originally introduced as part of IBM's initiative to provide businesses with powerful computing solutions, the IBM 600 servers have evolved to meet the growing demands of modern data environments.

One of the main features of the IBM 600 series is its capability for high scalability. The architecture of these servers allows organizations to expand their systems as needed, making it easier to adapt to changing business requirements. With various configurations available, users can select the specifications that best fit their workload, ranging from small businesses to large enterprises running mission-critical applications.

In terms of processing power, the IBM 600 is equipped with advanced multi-core processors. This technology allows for better parallel processing capabilities, enabling the server to handle multiple tasks simultaneously. The incorporation of IBM's Power architecture enhances the overall performance and energy efficiency of the servers, making them a suitable choice for organizations that rely heavily on data-intensive applications.

The IBM 600 series also excels in storage and memory capabilities. Users can equip the servers with large amounts of RAM and employ various storage options, including SSDs and traditional hard drives. This flexibility helps ensure that the systems can manage substantial data volumes while providing fast access speeds, essential for data-driven operations.

Security is another critical aspect of the IBM 600 series. IBM has integrated advanced security features to protect sensitive data, including encryption technologies and options for secure boot processes. This implementation is crucial for organizations that must comply with regulatory standards while safeguarding their information from potential breaches.

Additionally, the IBM 600 supports a variety of operating systems, including AIX, Linux, and Windows Server. This versatility makes it easier for businesses to integrate their existing software with the IBM infrastructure. Connectivity features, including multiple networking options, provide enhanced integration capabilities into organizational IT ecosystems.

Overall, the IBM 600 series combines powerful processing capabilities, flexible scalability, advanced security features, and a broad range of supported operating systems. These characteristics make it a compelling choice for enterprises looking to optimize their computing infrastructures and drive digital transformation initiatives. IBM continues to support and innovate within this server line, maintaining its relevance in the ever-evolving technology landscape.
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