[U-Boot] iMX6 DDR Calibration Value

[John Tobias]

Hi Fabio / Stefano,

May be you could help me to get some answer regarding with
calibrations value for DDR.

I have a 4 custom boards based on iMX6SL (2) Micron DDR and (2) Samsung DDR.

The boards has exact DDR footprints (like density, bus width and so
on). In fact the uboot that I am using works on both DDR chips.

I re-ran the DDR tools twice for each boards, entered the same
information. The tools returned different calibration values for each
boards but, the two results for each boards were the same.


e.g: board1

Read DQS Gating calibration
MPDGCTRL0 PHY0 (0x021b083c) = 0x412C0130
MPDGCTRL1 PHY0 (0x021b0840) = 0x01140118

Read calibration
MPRDDLCTL PHY0 (0x021b0848) = 0x3E404244

Write calibration
MPWRDLCTL PHY0 (0x021b0850) = 0x383C3E36

board2:

 Read DQS Gating calibration
 MPDGCTRL0 PHY0 (0x021b083c) = 0x412C0130
 MPDGCTRL1 PHY0 (0x021b0840) = 0x01140118

 Read calibration
 MPRDDLCTL PHY0 (0x021b0848) = 0x3E3E4244

 Write calibration
 MPWRDLCTL PHY0 (0x021b0850) = 0x383C3E36

Is there any procedures or rules of thumb you follow dealing with the
calibration settings?.

Regards,

John