Memory interleaving

The idea begin memory interleaving is to split up memory into multiple banks. Each of these banks can be accessed independently as they do not affect the memory outside them.

Types of interleaving

  1. In higher order interleaving, the higher order bits are used for selecting the bank, and the other bits are used as the offset
  2. Similarly, in lower order, the lower bits are used for chip selection, and the other are used as offset.
    ../attachments/interleaving_order.png
    Here, 4 bits for chip means that there are chips (or banks).
    Each of these memory modules can have their own -
  • Address buffer register (ABR)
  • Data buffer register (DBR)

Again, interleaving can be done in two ways -

  1. Consecutive words in a module: To go from one address to the next, we remain in the same module. Meaning, consecutive addresses are grouped together into modules.
  2. Consecutive words in consecutive modules: Addresses are grouped one by one into successive modules. So consecutive addresses end up in consecutive modules.