DDR3 Mirroring

also note that when mirroring is turned on, the only thing that happens is that the sequencer program changes slightly to account for the mirrored addressing on the odd ranks.

something might differ in the altera memory controller but in my project we don't use altera's controller, so i don't know.

forgetting to turn on mirroring for 2 rank unbuffered dimms is a common reason for calibration to fail on the 2nd rank. the uniphy configuration wizard does not do this automatically when 2 ranks is selected.