Help with External Bus Interface

Hi,
I am researching an application that needs a external flash and external SRAM interfaced to a MCU bus. I want to store the program memory on flash and use SRAM as data memory and I have few doubts..

I understand most common implementation is to copy the program memory from flash to sram and execute the program from SRAM. Is this correct and are there any other ways to implement this :?:

If I use processor with External bus interface, how does this work from software perspective? Is it some thing like putting correct data and address on the bus and set any registers to start data transfer :?: In this case does the external bus interface turn on the chip selects/read-write enables automatically :?:

Also what is the difference between external bus interface and DMA controller?

Thanks in advance
Smartsarath2003

Hi

1) Only if you want to make the processor run faster - you need to work from ram but you dont have to do that (for slow processor like 8051)

2)the processor see the external memory part, as a part of whole memory map

3)DMA - direct memory access it is a method for accessing the memory not throughthe cpu core

All the best

Bobi