after finding various bits of documentation i'm going to be testing out the following settings, which match the (known, calculated) impedance of the EOMA68-RK3288 board (around 50-60 ohms instead of 100-120 of the Reference Design):
http://www.skhynix.com/product/filedata/fileDownload.do?seq=6790 MR1: bits 9,6,2 = b001 = RZQ/4 = 60 ohms ODT bits 4,3 = b00 = CAS disabled bits 5,1 = b00 = RZQ/6 = 40 ohms output driver impedance bit 7 = 0 = write-leveling disabled bit 11 = 0 = TDQS disabled bit 12 = 0 = output disabling not enabled bit 10 reserved bit 8 reserved MR2: bits 10,9 = b01 = RZQ/4 = 60 ohms ODT bits 6,5,4 = b001 = CAS Write Latency 6 bits 3,2,1 = b100 = partial array self-refresh 3/4 array