TMS320C6701 expansion memory

I need to design a memory interface with 64 MBytes of SRAM (STATIC
RAM).

The DSP can adress 256 MBytes per "chip enable" but there are only 20
adress lines. In fact, it is made for SDRAM I know but STATIC RAM is
requested by the customer.

Because of that, I can only access 4 MBytes of Static RAM

I was thinking of making 16 banks with external glue logic and
software control of these banks.

Any other ideas ?

Thank you