Altera DDR SDRAM High-Performance Controllers and ALTMEMPHY IP - Manual (Page 30)

3–4 Chapter 3: Parameter Settings
ALTMEMPHY Parameter Settings
External Memory Interface Handbook Volume 3 June 2011 Altera Corporation
Section I. DDR and DDR2 SDRAM Controllers with ALTMEMPHY IP User Guide
Figure 3–2 shows the Preset Editor dialog box for a DDR2 SDRAM.
The Advanced option is only available for Arria II GX and Stratix IV devices. This
option shows the percentage of memory specification that is calibrated by the FPGA.
The percentage values are estimated by Altera based on the process variation.
Figure 3–2. DDR2 SDRAM Preset Editor