5.5.5. AXI extensions

The AXIM interface uses the ARCACHE and AWCACHE AXI signals and the ARSHARE, AWSHARE, ARINNER, and AWINNER extension signals to indicate the memory attributes of the transfer, as returned by the MPU:

In additional to these attribute extension signals the AXIM interface includes the following signals:


Indicates the source of the memory request. When set to:


The request has been generated by software running on the processor.


The request has been generated by a debug request on the AHB Debug (AHBD) interface.


The AWSPARSE is part of the write address channel signal group and indicates the burst uses sparse byte write-strobes, that is some of the beats of the write burst do not contain data. You can use this signal to optimize systems that bridge the AMBA 4 AXI protocol to AHB protocol.

See the Arm® AMBA® AXI and ACE Protocol Specification for valid encodings for all the AxCACHE and AxINNER signals.

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