ARM920T__MMU DOMAIN-EEWORLD

Collect

The ARM920T core provides 16 DOMAINs to describe different permission access modes. Many people will ask why there are 16 DOMAINs. There are only a few, one for 1M, one for 1K, one for 4K pages, and one for 64K pages. I asked the same question at first, but then I saw the manual and thought about the backward expansion of chip design. I can understand that there are two reasons.

1. This is because in order to expand, it is very likely that 2K pages or 8K pages will be made later. This is not impossible. At that time, it will be a big problem to ensure compatibility with the previous series.

2. A specification may have several access methods, and you can switch by modifying the corresponding register.

A collection of sections, large pages and small pages of memory, which can have their
access permissions switched rapidly by writing to the Domain Access Control Register
(CP15 register 3).

Keywords：ARM920T MMU Reference address：ARM920T__MMU DOMAIN

Previous article：ARM hardware and software handling of exceptions
Next article：nand write.jffs2 & nand write

Recommended ReadingLatest update time:2024-11-15 13:55

My Journey in Embedded Linux - Analysis of the Working Principle of ARM MMU

1. The Origin of MMU Many years ago, when people were still using DOS or older operating systems, computer memory was very small, generally calculated in K units. Correspondingly, the program size at that time was not large, so although the memory capacity was small, it could still accommodate the programs at that

[Microcontroller]

ARM MMU

Here is a summary of the three major functions of MMU: 1. Conversion from virtual address to physical address 2.Cache control 3. Memory access rights protection The Linux kernel uses three levels of page tables: PGD, PMD, and PTE. For many architectures, the PMD level has only one entry.

[Microcontroller]

S3C2410 MMU Technology Analysis

Many years ago, when people were still using DOS or older operating systems, computer memory was very small, generally calculated in K units. Correspondingly, the program size at that time was not large, so although the memory capacity was small, it could still accommodate the programs at that time. However, with the r

[Microcontroller]

Design of infrared communication system based on ARM920T

O Introduction With the rapid development of computer technology, communication technology and the Internet, embedded systems have been increasingly widely used. At the same time, the complexity of embedded systems is also increasing, and embedded operating systems have become the most important component. At pres

[Microcontroller]

Design of infrared communication system based on ARM920T

[Intermediate Tutorial] How to disable MMU, I-Cache and D-Cache?

Preface Taking the arm926ej-s core as an example, why is it said that chips with MMU, I-Cache and D-Cache have better operating processing efficiency? Compared with other chips without MMU, I-Cache and D-Cache, with MMU, the access address is safer, and with I-Cache, the instruction fetching rate is more efficient, be

[Microcontroller]

ARM920T_Core MMU and cache application analysis

1. Cache classification and application scenarios Cache is a high-speed buffer memory between the memory and the CPU, which is divided into icache (instruction cache) and dcache (data cache). If the cache is turned on, when the CPU is running, the instructions or data near the address of the instruction being run will

[Microcontroller]

ARM920T_Core MMU and cache application analysis

u-boot transplantation (8)---code modification---storage controller--MMU

1. Introduction to MMU 1.1 Virtual address and physical address 　　Build two applications, hello1.c and hello2.c, and then run: 　　hello1.c 　　　　hello2.c 　　　　The running results are as follows: 　　　　You can see that the addresses printed by the two results are the same, both are 0x601040, which means that both prog

[Microcontroller]

u-boot transplantation (8)---code modification---storage controller--MMU

Exynos4412 kernel transplantation (IV)—— MMU related knowledge analysis

[Microcontroller]

Popular Resources
Popular amplifiers