I am trying to implement the axi outstanding feature in CPP, i tried to search if there is already a model in CPP, did not find alot. Is there such model ? If not, Is there any diff in terms of READ and WRITE when it comes to outstanding ?

In additional…

PSTRB signal indicates which byte lanes to update during a write transfer.

it shows that the bus contain valid data, when PSTRB[3:0]=1111.

why we need bus instead of single bit PSTRB signal?