Measure the test taker's understanding about the differences between ARM system architecture () and arm.

This series of articles written by muge0913, reproduced please note the Source: http://blog.csdn.net/muge0913/article/details/7350789

1. clock frequency Improvement
Although the kernel architecture is the same, the ARM7 processor adopts a three-level pipeline structure of Feng nuiman, while the ARM9 adopts a five-level pipeline structure of Harvard, arm11 is an 8-level assembly line haver structure (from the beginning of arm9-has adopted the haver structure ). The added pipeline design improves clock frequency and parallel processing capabilities. The five-level pipeline can allocate each instruction processing time to five clock cycles, and five commands are executed simultaneously in each clock cycle. In common chip production processes, ARM7 generally runs at around MHz, while ARM9. arm11 first releases 350m ~ Kernel with MHz clock frequency,
Currently, the clock frequency is increased to 1 GHz.

2. instruction cycle Improvement
The improvement of the instruction cycle is of great help to improve the processor performance. The performance improvement depends on the overlapping of commands during code execution, which is actually a problem of the program itself. For the most advanced language, the performance is generally improved by about 30%.

3. MMU (Memory Management Unit)
Generally, there is no MMU (Memory Management Unit) in the arm720t and MMU in the arm720t ).
Arm9940t only has MPU, not a complete MMU.

Arm11 also has MMU.
This is important because MMU units are required for large operating systems, such as Linux and wince. This is to say, generally can only run a small real-time system such as UCOS-II, ECOs, and so on, and arm9-without this restriction, the general operating system can be transplanted. In fact, even if arm720t can support Linux, WinCE, and other systems, it is rare to use it because it is a little difficult to run such a large operating system at the operating speed of arm70. In addition, the application fields of the two are obviously different, and this is not necessary.

 

The following two figures show the architecture scene.

4. one thing that is fortunate in the transformation from ARM7 to arm11 is that arm11 can be backward compatible with software on arm7; in addition, the programming model and architecture infrastructure faced by developers are consistent.

The following figure shows the comparison of features: