The following are the guidelines for connecting to the DDR3 memory:
- DDR3 data nets have dynamic on-die termination (ODT) built into the controller and SDRAM. The configurations are 40 Ω, 60 Ω, and 140 Ω. VTT pull-up is not necessary.
- Characteristic impedance: Zo is typically 50 Ω, and Zdiff (differential) is 100 Ω.
DDR3 interfacing with SmartFusion2/IGLOO2 devices for 8-bit and 16-bit interfaces is shown in the following figures.
Figure 1. 8-Bit DDR3 Interface
Figure 2. 16-Bit DDR3 Interface
Note:
Short ECC_TMATCH_ OUT and ECC_TMATCH_ IN when using ECC bits.