A storage method for executable code under armv7m architecture

Abstract

The present invention provides a method for storing executable codes under the ARMv7m architecture, which is composed of five logic units including compiling and burning programs, startup programs, FPB related programs, execution programs, and bus exception handling programs, and a piece of RAM space is allocated through the FPB related programs Associated with an address that is not associated with the physical Flash, it is used as a storage space for storing executable code for the CPU core to obtain and execute machine instructions. At the same time, the RAM space can be dynamically updated to a new value, and can be reset and associated with a new Flash address by the FPB. In this way, the method of the present invention only uses a small piece of internal Flash to store the FPB management code, and can expand the storage space of the executable code of the CPU to 512MB by using a small RAM space and cheap off-chip Flash.

Description

Technical field [0001] The invention relates to a method for storing executable codes under the ARMv7m architecture, and in particular to a method for storing executable codes on an off-chip Flash without XIP under the ARMv7m architecture. Background technique [0002] In a computer system, the CPU needs to extract machine instructions first, then decode, and finally execute machine instructions. Machine instructions need to be stored in a memory directly addressable by the CPU before they can be extracted by the CPU. The memory that can be directly addressed by the CPU is generally on-chip RAM, off-chip parallel bus RAM, or parallel bus flash memory supporting XIP (execution on chip) functions. The unit storage space price of such a memory is relatively high, so an embedded MCU is generally not equipped with a large-capacity memory for storing executable codes. This limits the software functions that can be provided on the embedded MCU. If the memory of the parallel bus is ex...

AI Technical Summary

Problems solved by technology

However, the MCU of the ARM v7m architecture is difficult to be applied to devices in complex application scenarios due to the above-mentioned limitation of the space that can directly store executable code

This makes devices with complex application scenarios have to use ARM9 / ARM11 processors with low chip performance, or high-cost processors such as ARM v7r and ARM v7a, which in turn affects the cost performance of products.

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