Method for access to external memory

Abstract

The present invention discloses a method for visiting an external storage device. The present invention displays the bandwidth priority attribute of the physical features of the external storage device by setting up and determines whether the visit authority of the current visit request is entitled or not according to the judgment of the bandwidth priority attribute of the physical features of the external storage device, thus increasing the efficiency of the device to visit the external storage device. The continuous data visit tries to be operated on the same line of the same block to the largest extent, thus greatly increasing the efficiency of continuous visit of the external storage device. When implementing the data transmission by the former request, the command and the address of the current visit request are parallelly sent out, thus reducing the time consumption of the transmission command delay; the time consumption of the bus switch is reduced by ensuring that the continuous data visit is writing or reading.

Description

technical field [0001] The invention relates to memory processing technology, in particular to a method for accessing external memory. Background technique [0002] In an integrated system on chip (SoC), it includes multiple parallel processing functional modules such as processor, DMA, hardware accelerator, peripheral hardware, etc. These functional modules will access off-chip memory such as SDRAM, DDR memory, etc. as required. [0003] Since the functional modules such as the processor, DMA, and hardware accelerator operate independently, in practical applications, the SDRAM memory may be accessed by multiple functional modules at the same time. However, according to the physical characteristics of the SDRAM memory, at the same time, the SDRAM memory only allows There is a read and write access. In order to solve this problem, the access to the external memory needs to grant the access right of the external memory to the access request of a certain functional module thro...

AI Technical Summary

Problems solved by technology

[0009] At present, the bus arbitration unit in a general SoC arbitrates a request from multiple master devices according to the request sequence or the module priority of the master device, and directly sends it to the SDRAM memory without considering the unique delay characteristics of the SDRAM memory itself.

However, when there are more and more parallel functional modules in external devices such as complex SoC chips, and the computing and processing capabilities of functional modules are getting stronger and stronger, the low storage efficiency of SDRAM memory directly seriously reduces the access efficiency of external devices.

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