Hello,
Your ASIC vendor will have utilities that will help with power exploration. They may have models for memories where you can set up access rates and thereby calculate power consumption. Sometimes the datasheets of the memories themselves will give you guidance on how to design for the access rates. At a low architectural level, you can use the Energy curve vs. operating voltage of the memory in consideration for reducting power. At a higher level, you can use multiple levels of fast/slow memories based on performance and power requirements.
A good book to refer to is . . .
Ultra Low-Power Electronics and Design by Enrico Macii
Best Regards,
--
Adam