Rev 0.7 / Apr. 2005

47

Preliminary

HY27UF(08/16)1G2M Series

HY27SF(08/16)1G2M Series

1Gbit (128Mx8bit / 64Mx16bit) NAND Flash

Application Note

1. Power-on/off Sequence

After power is on, the device starts an internal circuit initialization when the power supply voltage reaches a specific

level. The device shows its internal initialization status with the Ready/Busy signal if initialization is on progress. While

the device is initializing, the device sets internal registeries to default value and generates internal biases to operate

circuits. Typically the initializing time of 20us is required.

Power-off or power failure before write/erase operation is complete will cause a loss of data. The WP# signal helps

user to protect not only the data integrity but also device circuitry from being damaged at power-on/off by keeping

WP# at VIL during power-on/off.

For the device to operate stably, it is highly recommended to operate the device as shown Fig.33.

Figure 34: Power-on/off sequence