Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Memory Presets for DDR2 SDRAM High Performance Controller in SOPC Builder

I need to interface with the Micron DDR2 SDRAM (MPN:MT47H32M16 HR-25E:G) in SOPC Builder, however, the available memory preset cannot be found in the "Memory Presets" list. There is an opti...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

Well, timing parameters can have minimums, maximums, or both. How much margin to leave for each? I'm making two presets, one exactly at the borders of the ranges, and one being a little relaxed, maybe 10%, in theory sacrificing performance for reliability.

However there are some glitches to this approach. For example, tAC in the datasheet is -400ps < tAC < 400ps, but the presets window requires a value from 350ps to 750ps. Seems a bit strange, since I'd like to put 0ps (right in the middle of the range), but I guess the closest I can get is 350ps. Am I missing something?