Hidden Hynix DDR Enable Command

While sniffing traffic on a Hynix NAND chip (H27Q1T08EM6R ID: ad 3c 19 a3) we found a hidden command to change the read mode from NON-DDR to DDR which effectively doubles the read throughput of the chip.

Cmd 0xEF
Addr 0x01
Data 0x20 0x00 0x00 0x00