External Memory Interface Handbook Volume 3: Reference Material: For UniPHY-based Device Families

ID 683841
Date 3/06/2023
Public
Document Table of Contents

4.6.4.6. Interleaving Options

The controller supports the following address-interleaving options:
  • Non-interleaved
  • Bank interleave without chip select interleave
  • Bank interleave with chip select interleave

The following interleaving examples use 512 megabits (Mb) x 16 DDR3 chips and are documented as byte addresses. For RAMs with smaller address fields, the order of the fields stays the same but the widths may change.

Non-interleaved

RAM mapping is non-interleaved.

Figure 44. Non-interleaved Address Decoding


Bank Interleave Without Chip Select Interleave

Bank interleave without chip select interleave swaps row and bank from the non-interleaved address mapping. This interleaving allows smaller data structures to spread across all banks in a chip.

Figure 45. Bank Interleave Without Chip Select Interleave Address Decoding


Bank Interleave with Chip Select Interleave

Bank interleave with chip select interleave moves the row address to the top, followed by chip select, then bank, and finally column address. This interleaving allows smaller data structures to spread across multiple banks and chips (giving access to 16 total banks for multithreaded access to blocks of memory). Memory timing is degraded when switching between chips.

Figure 46. Bank Interleave With Chip Select Interleave Address Decoding