UK HS code duty optimization

List of contents of this article:

• 1,UK HS code duty optimization How does the arm system use the SWI function
• 2, What can be used in ARM architectureWork system_arm operating system
• 3, What is ARM platform
• 4, Nokia LuMia1020 brush Win10ARM tutorial and experience sharing
• 5, What does ARM64 refer to? What's the difference with x86?

How does the arm system deal with SWI function

SwiFunction function is a dispersal function, and its function is to jump toIt is executed at the corresponding function, that is, if the parameter is 1, the function will jump to IRQEnable to execute and enable the IRQ interruption.

swi is the abbreviation of "SoftWare Interrupt", that is, software interruption, and is also an assembly instruction of arm. SWI instructions are used to generate software interruptions so that user programs can call the system routines of the operating system.

For example: When the software interrupts the exception SWI, the instructions MOV PC and R14_svc always return to the next instruction, whether SWI is executed in the ARM state or in the Thumb state. Copy CPSR to the corresponding SPSR. According to the exception type, force the running mode bit of CPSR.

Management mode (svc, Supervisor Mode).The protection mode used by the operating system. Enter when the system is reset or the software interrupt instruction SWI is executed. ( 5) Data access termination mode (abt, Abort Mode).

In addition, when an exception occurs when the processor is in the thumb state (such as irq, fiq, undef, abort, swi, etc.), the exception is automatically switched to the thumb state when the exception is returned. Enter the arm state: When the state bit of the operand register is 0, the microprocessor can switch from the thumb state to the arm state when executing the bx instruction.

The function of interrupting SWI instructions by the software has been improved; the user register operation is used when the processor system mode introduces the privileged mode; empty some unused instructionsInter-capture is undefined instruction ARM version V: V5 version architecture V5 version architecture adds some new instructions on the basis of V4 version, and ARM10 and Xscale both adopt this version of architecture.

ARM architecture can use any operating system_arm operating system

1, and arm can do industrial control, but 51 is a simple 8-bit single-chip computer, so So that you can only do some relatively simple controls. But 51 can also be used on some simple systems, such as uCOS-2. And arm is a 32-bit processor with strong processing power.

2. Flexible instruction set support: ARM instruction set supportIt has a variety of data types and operations, including logical operations, arithmetic operations, branch jumps, comparisons and branches, etc., which is conducive to the realization of various complex program logics.

3. Similarly, programs compiled on the x86 machine cannot be executed on the arm machine. The system is not universal.

4. Yes, for example, the previous WindowsRT, although different from the X86 version of Windows, is at least a real Windows system. In an ARM architecture machine, the way the peripheral device connects the processor.

What is ARM platform

1. ARM architecture, once called Advanced RISCMachine) was earlier known as Acorn RISC Machine, which is a 32-bit simplified instruction set (RISC) processor architecture. There are also derivative products based on ARM design, including Marvell's XScale architecture and Texas Instruments' OMAP series.

2. The establishment of "ARM Architecture Cloud Platform" is based on the ARM architecture central processor produced by Guizhou Huaxintong Semiconductor Technology Co., Ltd., which makes full use of the advantages of high performance, low power consumption and low cost of the server CPU.

3. What is the ARM platform? It is a processor of PPC. ARM is the abbreviation of advanced RISC microprocessor.

4. ARM is a processor architecture, itsThe full name is Advanced RISC Machine, which is an advanced simplified instruction set computer. ARM processor architecture is a streamlined instruction set (RISC) computer architecture that aims to improve processor performance and reduce costs and power consumption. The application field of ARM processor architecture is very wide.

5. ARM is a British company, and its meaning is Advanced RISC Microprocessor.

6. The ARM we often talk about is actually a supporting property right of the CPU structure provided by the British ARM company. The CPUs of all kinds of mobile smart devices and smart consumer electronic products we commonly use ARM architecture. At present, in the PC market, Apple's self-developed M1 chip is also based on ARM architecture.

Nokia Lumia1020 brush Win10ARM tutorial and experience Check and share

1. Reset the mobile phone, do not turn it on, connect the computer (must win7), and reinstall the computer. ( Remember to back up) The last step is very important. Don't move when the mobile phone is connected to the computer. Take a nap and get up to wp8.

2. Open the browser and enter the Win10 ARM image official website. According to your device model, download the corresponding Win10 ARM image file and save it anywhere on the computer. Unzip the newly downloaded Win10 ARM image file and write down the decompression path.

3. At present, the way to upgrade the Win10 system of Lumia mobile phones is important to check and update the Win10 system through the "windows insider" application. In this regard, we need the "Windows Insider" tool, which can be found and downloaded in the "App Store" or obtained from the official website of "Microsoft".

4. Start Win32DiskImager and open the mirror file;Select the USB disk character, and then click the "Write" button to start making a boot disk.

5. Download the ROM package. Search the download address of Nokia Lumia1020 Android ROM package on the Internet and download the corresponding ROM package. After the download is completed, unzip the ROM package. Install the ADB driver. Connect the Nokia Lumia1020 to the computer and install the ADB driver. The computer can find the device in the device manager. Enter the flash mode.

What does ARM64 refer to? What's the difference with x86?

ARM64 refers to the processor architecture running in the state of AArch64. ARM64 and x86 mainly have certain differences in architecture.

x86 and ARM are two different processor architectures, which have obvious differences in instruction sets, application fields and performance characteristics. The following are the main differences between x86 and ARM architecture. Instruction set architecture: x86 adopts a complex instruction set computing (CISC) architecture, while ARM adopts a simplified instruction set computing (RISC) architecture.

x86 architecture and ARM architecture have the following differences: First, they pursue different goals. X86 mainly pursues performance, but it will lead to high power consumption and not energy saving, while ARM pursues energy saving and low power consumption, but its performance is worse than that of x86. Secondly, they have different fields of application.

The pursuit of different X86 mainly pursues performance, but it will lead to high power consumption and non-energy saving, while ARM pursues energy saving and low power consumption, but the performance is poorer than that of X86.