WO R K I N G W I T H T H E C P U

R7:Cache Operations register

R 7 : C a c h e O p e r a t i o n s r e g i s t e r

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Register R7 controls the caches and write buffer. The function of each cache operation is selected by the opcode_2 and CRm fields in the MCR instruction that writes to CP15 R7. Writing other opcode_2 or CRm values is UNPREDICTABLE.

Reading from R7 is UNPREDICTABLE, with the exception of the two test and clean operations (see “Cache operation functions” on page 95 and “Test and clean DCache instructions” on page 96).

Write instruction Use this instruction to write to the Cache Operations register:

MCR p15, opcode_1, Rd, CRn, CRm, opcode_2

Cache functions This table describes the cache functions provided by register R7.

Function

Description

 

 

Invalidate cache

Invalidates all cache data, including any dirty data.

 

 

Invalidate single entry using either index or

Invalidates a single cache line, discarding any dirty data.

modified virtual address

 

Clean single data entry using either index or modified virtual address

Writes the specified DCache line to main memory if the line is marked valid and dirty. The line is marked as not dirty, and the valid bit is unchanged.

Clean and invalidate single data entry using

Writes the specified DCache line to main memory if the

wither index or modified virtual address.

line is marked valid and dirty. The line is marked not valid.

 

 

Test and clean DCache

Tests a number of cache lines, and cleans one of them if

 

any are dirty. Returns the overall dirty state of the cache in

 

bit 30. (See “Test and clean DCache instructions” on

 

page 96).

 

 

Test, clean, and invalidate DCache

Tests a number of cache lines, and cleans one of them if

 

any are dirty. When the entire cache has been tested and

 

cleaned, it is invalidated. (See “Test and clean DCache

 

instructions” on page 96).

 

 

Prefetch ICache line

Performs an ICache lookup of the specified modified

 

virtual address. If the cache misses and the region is

 

cachable, a linefill is performed.

94Hardware Reference NS9215

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Digi NS9215 manual A c h e O p e r a t i o n s r e g i s t e r, Function Description
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NS9215 specifications

The Digi NS9215 is a powerful solution designed for industrial applications that require reliable connectivity and robust performance. Built on a foundation of advanced technologies, the NS9215 serves as a versatile networking device that meets the demands of automation, remote monitoring, and data acquisition.

One of the standout features of the Digi NS9215 is its multi-protocol support. It is capable of handling various communication protocols, including Ethernet, Serial, and Wireless, making it ideal for integration into heterogeneous environments. This flexibility enables users to connect legacy devices to modern networks seamlessly, facilitating smoother data communication across different platforms.

The NS9215 is equipped with powerful processing capabilities, featuring an integrated processor that ensures efficient data handling. This enables the device to perform complex data tasks without compromising performance. Its high-speed connectivity options also allow for rapid data transmission, which is crucial for real-time applications in industrial settings.

Another critical characteristic of the Digi NS9215 is its reliability in harsh environments. Built to withstand extreme temperatures, humidity, and electrical interference, this device assures consistent operation even in challenging conditions. Its rugged design minimizes the risk of failure, making it suitable for deployment in various industrial environments.

Security is a top priority for the Digi NS9215. It comes with advanced security features that protect sensitive data during transmission and prevent unauthorized access. Employing encryption protocols and secure authentication methods, the NS9215 ensures that data integrity and confidentiality are maintained throughout its operation.

The user-friendly interface of the NS9215 allows for easy configuration and management. This ease of use reduces the time required for installation and setup, enabling quick deployment in field operations. Additionally, remote management capabilities enhance operational efficiency, allowing users to monitor device performance and make adjustments from anywhere.

Furthermore, the NS9215 supports extensive scalability options. As organizations grow and evolve, the ability to scale up or adapt the networking capabilities becomes essential. With its modular design, the NS9215 can easily accommodate additional devices and protocols, ensuring longevity and continued relevance in a rapidly changing technological landscape.

In conclusion, the Digi NS9215 is a robust networking device designed for a wide range of industrial applications. Its multi-protocol support, reliability, security features, user-friendly interface, and scalability make it a valuable addition to any industrial network infrastructure, delivering performance and efficiency that businesses can depend on for critical operations.
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