the refresh action of ddr2 hpc ii controller ?

when i setup the ddr2 ip megawizard ,i select hpc ii ,and i select "Enalbe User Auto_refresh Control" selection too,and there three signals are producted ,those are local_refresh_req ,local_refresh_ack,local_refresh_chip,but in the example of the ddr2 ip ,local_refresh_req and local_refresh_chip are assigned to 1'b0,

in this situation , the ddr2 can be refreshed or not?

i can write to and read from the ddr2,but i am puzzled,

I think the data should be lost because the ddr2 is not be refresh,

is the ddr2 chip refreshed or not?

can anybody tell me ?