"dbs" in sopc generated vhdl code

in sopc generated systems including avalon slave components,always we see the avalon slave components' address pins are fed by their corresponding arbitrator entities' A_EXT(A_SRL .... )) operations output pins,well this is normal operation of SOPC. (Because address is 32 bit and component address inputs are 2 or 3 bits etc.)

But in some components, we see the components' corresponding arbitrator entities have some additional dbs pin outputs for feeding the address pins of their corresponding components. I did not justify the meaning of such operation and attached a doc file having a basic and very dummy avalon slave component's vhdl code,and lpb_mpc5200b_to_avalon_0_avalon interface and lpb_mpc5200b_to_avalon_0_avalon_arbitrator entity's interface code.

Does anybody know why the dbs pins are generated and what do they mean?

best,