DS90UB954-Q1EVM: Two DS90UB953(with different remote slave address) to DS90UB954, how to access these two 953 by HOST?

Dear Sir,

I found only one SER_ ID(0x5b) and SER_ALIAS_ID(0x5c) registers are supported in 954, which 953 slave id is mapped into this register and how to access these two 953 by HOST?

Can  HOST send init commands to these two 953s simultaneously by broadcast method? it will save a lot init time.

Thanks,

David