In the Spartan-6 FPGA Memory Controller User Guide (UG388), on page 38, Figure 3-3 shows that the PLL output, CLKOUT2, is used for calibration (see first snapshot below).
However, on the next page, page 39 (Modifying the Clock Setup) it says that CLKOUT2 is for the user clock, while CLKOUT3 is for calibration (see second snapshot below)
Which is correct?
Figure 3-3 is incorrect.
CLKOUT2 is for UI logic (traffic generation or user traffic).
CLKOUT3 is for the DRP clock, which is used by the calibration.
In Figure 3-3, CLKOUT2 should read CLKOUT3.
Fixed Version: No plans to be fixed in (UG388)
9/9/2014 - Initial Release