General Description
   Toggle DDR is a NAND interface for high performance applications which support data read and write operations using bidirectional DQS.
   Toggle DDR NAND has implemented ’Double Data Rate’ without a clock. It is compatible with functions and command which have been supported in conventional type NAND(i.e. SDR NAND) while providing high data transfer rate based on the high-speed Toggle DDR Interface and saving power with separated DQ voltage. For applications that require high capacity and high performance NAND, Toggle DDR NAND is the most appropriate.
   Toggle DDR1.0 NAND supports the interface speed of up to 100 MHz, which is faster than the data transfer rate offered by SDR NAND. Toggle DDR NAND transfers data at high speed using DQS signal that behaves as a clock, and DQS shall be used only when data is transferred for optimal power consumption.
   This device supports both SDR interface and Toggle DDR interface. When starting, the device is activated in SDR mode. The interface mode can be changed into Toggle DDR interface utilizing specific command issued by the Host.