how to set multiple ddr_hp_controller pin-name prefixes in one project?

Thanks again Std_logic!

As you suggested, without any prefix editing, I have used the default variation_pin_assignment.tcl to compile my project, which instantiated a ddr_hp_controller twice with a_mem and b_mem interfaces. The compiling has been through without error message . But when I looked at that "variation_phy_autodetectedpins.tcl" , only the pins for a_mem port are listed. Why my b_mem port pins are not there? Is the b port really connected? I am confused.

Your input is most appreciated. Thanks!