HY27UG088G5B Datasheet, PDF (17/53 Pages) Hynix Semiconductor – 8Gb NAND FLASH

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HY27UG088G(5/D)B Series
8Gbit (1Gx8bit) NAND Flash
4. OTHER FEATURES
4.1 Data Protection & Power On/Off Sequence
The device is designed to offer protection from any involuntary program/erase during power-transitions. An internal
voltage detector disables all functions whenever Vcc is below about 2.0V(3.3V device). WP pin provides hardware pro-
tection and is recommended to be kept at VIL during power-up and power-down. A recovery time of minimum 10us is
required before internal circuit gets ready for any command sequences as shown in Figure 26. The two-step command
sequence for program/erase provides additional software protection.
4.2 Ready/Busy.
The device has a Ready/Busy output that provides method of indicating the completion of a page program, erase,
copy-back and random read completion. The R/B pin is normally high and goes to low when the device is busy (after a
reset, read, program, erase operation). It returns to high when the internal controller has finished the operation. The
pin is an open-drain driver thereby allowing two or more R/B outputs to be Or-tied.
Because pull-up resistor value is related to tR(R/B) and current drain during busy (Ibusy), an appropriate value can be
obtained with the following reference chart (Fig 27). Its value can be determined by the following guidance.
Rev 0.2 / Jan. 2008
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