Hello C.Himabindu,
Are you referring to the register setup that can be generated by the i.MX6SL LPDDR2 Register Programming Aid?
https://community.nxp.com/docs/DOC-105968
In that case the best source of information is the Reference Manual, albeit it’s a bit cumbersome and there are several settings to take care, which is why the programming aid is a very useful tool.
I hope this helps!
Regards,