Why AXI4 changed the definition of AxCACHE?

Hi,

In AXI4, spec changed the definition of the definition of AxCACHE[3:2] from Write Allocate/Read Allocate to be Allocate/Other Allocate.

But is there any concrete reason for this change? Actually I found some related statements from spec, but I couldn't get the point.

"The change to the definition of AxCACHE means that these signals can differ for a read and write transaction to the same location."

Does it mean with this change, we can distinguish the transaction type (i.e., read/write) from AxCACHE signal? However, from memory type encoding, the AxCACHE of "Read and Write-allocate" are the same for both read and write transactions.

Thanks.

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