List of Registers

Table 53. I/O CSR

• Byte Offset: 027:026h

Bit

Name

R/W

Description

 

 

 

 

 

 

 

This bit reflects the status of the Secondary Own bit used for

 

Downstream

 

generating I/O transaction on the secondary bus.

 

 

When 0, the Downstream I/O Address and Downstream I/O

0

I/O Own Bit

R

Data registers are not owned.

 

Status

 

 

 

• When 1, the Downstream I/O Address and Downstream I/O

 

 

 

 

 

 

Data registers are owned by a master.

 

 

 

 

 

 

 

Enables the 21555 to perform downstream indirect I/O transactions.

 

 

 

When 0, the 21555 will not initiate a I/O transaction on the

 

 

 

secondary interface when the Downstream I/O Data register is

 

Downstream

 

accessed. The Downstream I/O Data register is treated as a

1

R/W

reserved register.

I/O Control

 

 

• When 1, the 21555 is enabled to perform downstream I/O

 

 

 

 

 

 

transactions when the Downstream I/O Data register is

 

 

 

accessed with an I/O transaction.

 

 

 

• Reset value is 0

 

 

 

 

7:2

Reserved

R

Reserved. Read only as 0.

 

 

 

 

 

 

 

This bit reflects the status of the Primary Own bit used for generating

 

Upstream

 

I/O transaction on the Primary bus.

 

 

When 0, the Upstream I/O Address and Upstream I/O Data

8

I/O Own Bit

R

registers are not owned.

 

Status

 

 

 

• When 1, the Upstream I/O Address and Upstream I/O Data

 

 

 

 

 

 

registers are owned by a master.

 

 

 

 

 

 

 

Enables the 21555 to perform upstream indirect I/O transactions.

 

 

 

When 0, the 21555 will not initiate an I/O transaction on the

 

 

 

primary interface when the Upstream I/O Data register is

 

 

 

accessed. The Upstream I/O Data register is treated as a

9

Upstream

R/W

reserved register.

I/O Control

• When 1, the 21555 is enabled to perform upstream I/O

 

 

 

 

 

transactions when the Upstream I/O Data register is accessed

 

 

 

with an

 

 

 

I/O transaction.

 

 

 

• Reset value is 0

 

 

 

 

15:10

Reserved

R

Reserved. Read only as 0.

 

 

 

 

Table 54. Lookup Table Offset Register

Table 54 and Table 55 are registers that provide a method for the lookup table to be accessed using I/O transactions, although memory transactions can use either this mechanism or direct access of the lookup table.

Byte Offset: 028h

Bit

Name

R/W

Description

 

 

 

 

 

 

 

This register contains the byte offset of the Lookup Table entry to be

7:0

LUT_OFFSET

R/W

accessed. The access is initiated when the Lookup Table Data register

is either read or written. This register should be written before the

 

 

 

 

 

 

Lookup Table Data register is accessed.

 

 

 

 

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21555 Non-Transparent PCI-to-PCI Bridge User Manual

Page 146
Image 146
Intel 21555 user manual O Csr, Lookup Table Offset Register, Lutoffset

21555 specifications

The Intel 21555 is a prominent microprocessor developed by Intel, designed to cater to a variety of computing needs. This processor marks a significant step forward in Intel's lineup and underscores the company's commitment to advancing technology in personal computing, enterprise solutions, and beyond.

One of the standout features of the Intel 21555 is its advanced architecture. It utilizes a multi-core design, enabling improved performance through parallel processing. This architecture allows multiple applications to run seamlessly without a decline in speed. The cores are built on a cutting-edge manufacturing process that enhances energy efficiency while maintaining high clock speeds.

The Intel 21555 supports a wide range of technologies, including Intel Turbo Boost, which enables dynamic adjustments to the processor’s performance based on workload demands. This feature allows the processor to accelerate its speed during intensive tasks, providing users with a responsive experience when it matters the most.

Another key characteristic of the Intel 21555 is its support for integrated graphics. With Intel UHD Graphics technology, users can enjoy enhanced visuals for everyday tasks such as video playback, web browsing, and light gaming. This eliminates the need for a separate graphics card for many users, particularly in home office or light gaming scenarios.

Security is a significant focus in the design of the Intel 21555. It includes built-in hardware-based security features like Intel Trusted Execution Technology and Secure Boot. These features help protect against various types of threats, ensuring that user data remains secure from malicious attacks.

The Intel 21555 is also optimized for use with Intel's platform technologies, including Intel Optane memory and Intel Rapid Storage Technology. These technologies work together to deliver faster boot times and improved system responsiveness, making computing more efficient for users.

Furthermore, the Intel 21555 is designed to support virtualization technologies, allowing multiple operating systems to run concurrently without compromising performance. This is particularly useful for developers and businesses that rely on virtualization for testing and development environments.

In summary, the Intel 21555 is a powerful and versatile processor that reflects Intel's ongoing innovation in the computing space. With its multi-core architecture, enhanced graphics capabilities, strong security features, and advanced technologies, it stands out as an excellent choice for a wide range of applications, serving both casual users and professionals alike.