Hi,
I'm assuming you already have a flash setup in your SOPC builder system. Create a new SRAM component in SOPC builder using make new component. Define the attributes of the sram. Drop it into your SOPC system connect it to the avalon bus. The Data bus and address lines will be shared by both the SRAM and the flash. When you update your nios symbol in the bdf file(in quartus) it creates 3 control lines, Chip Select, Output enable and write Enable to control the SRAM. The address and data are connected automatically in quartus, so make sure they are on your systems PCB board. If you require them to be on seperate busses i expect you have to add a new avalon bus for each individual memory component.
Mark
