1)according specification The SPLIT and RETRY responses provide a mechanism for slaves to release the bus when they are unable to supply data for a transfer immediately.when the slave issue SPLIT?when slave issue RETRY?is there any specific condition is there?
Please can you explain what you are looking at AMBA 2 AHB for ?
This is a really old version of the protocol, and I wouldn't expect current designs to use it as it isn't great for performance having all masters sharing one bus, so you would be far better looking at AMBA 3 AHB-lite or AMBA 5 AHB.
If this is purely for acedemic interest, please say so.
To answer your question, from the master's perspective the master behaves the same for both a SPLIT or RETRY response, it simply re-requests access to the bus and attempts to "retry" the failed access.
RETRY just tells the bus arbiter to only keep the current master granted if it is the highest priority requestingf master, so it only allows higher priority masters to gain access to the shared bus, and lower priority requesting masters remain stalled. But RETRY is simple for the slave to issue, and will work for some applications.
SPLIT tells the bus arbiter to no longer grant this master, so allows both higher and lower priority masters requesting the bus to gain access. But it requires more complexity in the slave design as it now has to generate a SPLIT output to tell the arbiter when a SPLIT master can be re-granted.
So SPLIT is better for every master's performance but requires added complexity in the slave and arbiter designs, whereas RETRY is not as good as SPLIT for performance but is simple for the slave to implement.