Instruction set is described in EREF and VLEPEM manuals:
http://www.nxp.com/files/32bit/doc/ref_manual/EREF_RM.pdf
http://www.nxp.com/files/32bit/doc/ref_manual/VLEPEM.pdf
I am also attaching list of instructions NOT supported by e200z4251n3 core
Hope it helps