I got ddr3 calibration value by running The i.MX 6/7 Series DDR stress test tool, eg.
MMDC registers updated from calibration
Write leveling calibration
MMDC_MPWLDECTRL0 ch0 (0x021b080c) = 0x00000000
MMDC_MPWLDECTRL1 ch0 (0x021b0810) = 0x001F001F
Read DQS Gating calibration
MPDGCTRL0 PHY0 (0x021b083c) = 0x4154014C
MPDGCTRL1 PHY0 (0x021b0840) = 0x00000000
Read calibration
MPRDDLCTL PHY0 (0x021b0848) = 0x40402E32
Write calibration
MPWRDLCTL PHY0 (0x021b0850) = 0x40403830
Success: DDR calibration completed!!!
But some calibration values may vary each run on the same board or run on different boards.
eg.
MPDGCTRL0 PHY0 (0x021b083c) = 0x4154014C
MPDGCTRL0 PHY0 (0x021b083c) = 0x41500148
MPDGCTRL0 PHY0 (0x021b083c) = 0x414C0148
How do i choose this calibration value？ the max one? the min one? or average of the 3 values？
