List of Registers

Table 61. Primary and Secondary Command Registers (Sheet 2 of 2)

 

 

 

 

 

 

 

 

Offsets

 

 

Primary Command

Secondary Command

 

 

 

 

 

 

 

 

 

Primary byte

 

05:04h

45:44h

 

 

 

 

 

 

 

 

 

Secondary byte

 

45:44h

05:04h

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bit

Name

R/W

Description

 

 

 

 

 

 

 

 

7

Wait Cycle

R

Reads as zero to indicate the 21555 does not perform address or data

 

Control

stepping.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Controls the enable for SERR# on the corresponding interface.

 

 

SERR#

 

• When 0, SERR# cannot be driven by the 21555.

 

8

R/W

• When 1, SERR# may be driven low by the 21555 under the

 

Enable

 

 

 

conditions described in Chapter 12.

 

 

 

 

 

 

 

 

• Reset value is 0.

 

 

 

 

 

 

 

 

 

 

 

Controls the ability of the 21555 to generate fast back-to-back

 

 

 

 

transactions on the corresponding bus.

 

9

Fast

R/W

• When 0, the 21555 does not generate back-to-back transactions.

 

Back-to-Back

• When 1, the 21555 is enabled to generate back-to-back

 

 

Enable

 

 

 

 

transactions.

 

 

 

 

 

 

 

 

 

 

 

 

• Reset value is 0.

 

 

 

 

 

 

 

 

 

 

15:10

Reserved

R

Reserved. Returns 0 when read.

 

 

 

 

 

 

 

 

 

Table 62. Primary and Secondary Status Registers (Sheet 1 of 2)

The bits described in Table 62 reflect the status of the 21555 primary interface for the Primary Status register, and of the secondary interface for the Secondary Status register. W1TC indicates that writing a 1 to that bit clears the bit to 0. Writing a 0 has no effect.

 

Offsets

 

Primary Status

Secondary Status

 

 

 

 

 

 

 

 

Primary byte

 

07:06h

47:46h

 

 

 

 

 

 

 

 

Secondary byte

 

47:46h

07:06h

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bit

Name

R/W

 

Description

 

 

 

 

 

 

 

 

 

 

3:0

Reserved

R

 

Reserved. Returns 0 when read.

 

 

 

 

 

 

 

 

4

ECP Support

R

 

Enhanced Capabilities Support Indicator. Reads as 1 to indicate that

 

the Enhanced Capabilities Port is supported.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

66 MHz Capable Indication.

 

 

 

 

 

 

 

Reads as 0 to indicate that the corresponding interface operates at a

5

66 MHz Capable

R

 

maximum frequency of 33 MHz.

 

Reads as 1 to indicate that the corresponding interface is 66 MHz

 

 

 

 

 

 

 

 

 

 

capable.

 

 

 

 

 

 

 

Product derivatives hardcode this to either 0 or 1.

 

 

 

 

 

 

 

 

6

Reserved

R

 

Reserved. Returns 0 when read.

 

 

 

 

 

 

 

 

7

Fast Back-to-Back

R

 

Reads as 1 to indicate that the 21555 is able to respond to fast

Capable

 

back-to-back transactions on the corresponding interface.

 

 

 

 

 

 

 

 

 

 

 

 

150

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

Page 150
Image 150
Intel 21555 Primary and Secondary Command Registers Sheet 2, Primary and Secondary Status Registers Sheet 1, Serr#

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.