Device for connecting processor and BOOT FLASH and implementing method

Abstract

The invention discloses a connecting device between a processor and a BOOT FLASH, and a realization method thereof. The connecting device comprises a bus logic processing unit, a controlling unit and a startup register; the startup register is used for storing the start identification of the BOOT FLASH; the controlling unit is used for monitoring the start identification and determines whether the BOOT FLASH is started successfully or not, and if so, a control signal for directly transmitting a bus signal is sent to the bus logic processing unit; and if not, a control signal which performs reversal processing to the data bus signal in the bus according to the byte order and then transmits the data bus signal is sent to the bus logic processing unit; the bus logic processing unit is connected with the processor in a default connection manner, and the corresponding connection manner can also be adopted for connection according to the byte order of the BOOT FLASH. The dynamic selection of the connection manner of the byte orders between the CPU with different byte orders and the BOOT FLASH can be realized, the method is simple, and the cost is lower.

Description

technical field [0001] The invention relates to a connection device between processors with different byte sequences and BOOT FLASH (boot flash memory) and its realization method. Background technique [0002] In the field of embedded system design, regardless of hardware design or software design, byte order is a problem that must be considered. The so-called byte order is the order of bytes, which is the access order of data larger than one byte in the memory. There are two ways: big endian and little endian. . [0003] Big-endian is the way in which bytes are arranged when storing more than two bytes of data in a memory with a byte-unit address. At this time, the byte of the big-endian MSB is stored in ascending order of the address of the memory. Endianness is the order in which bytes are arranged, not bits, and the order in which bits are arranged within a byte does not change. [0004] figure 1 An illustration showing big-endian byte ordering. As shown in the figu...

AI Technical Summary

Problems solved by technology

However, when the memory uses BOOT FLASH, the byte order cannot be changed by software, which brings great risks to hardware design.

[0010] The Chinese patent application number 200410030047.9 discloses a data sharing device and a processor for sharing data between processors with different byte sequences. The realization of this invention is mainly based on the conversion of the data address of the processor. When BOOT FLASH cannot change the byte order by software, but the processor needs to be greatly improved, which consumes a large cost and is not conducive to the implementation

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