In reply to MICRO_91:
My understanding is, for a single set of registers(instances), multiple reg_maps can exists.
reg_maps are used to calculate final adress (map_base_addr+reg_offset).Ex., if an IP has multiple interfaces, and base address of IP could be different through different interfaces. This requires two different reg_maps. You can write through one interface and read through other interface, read will reflect write value even though maps are different.
I realized in this scenario its better to use uvm_frontdoor_seq instead of ral adapter. Any ral access invocation will call user defined seq extended from uvm_frontdoor_seq, where we can perform the register access normally through frontdoor.