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64-megabit
(4M x 16)
Page Mode
2.7-volt Flash
Memory
AT49BV640
AT49BV640T
Preliminary
Description
The AT49BV640(T) is a 2.7-volt 64-megabit Flash memory. The memory is divided
into multiple sectors for erase operations. The device can be read or reprogrammed
off a single 2.7V power supply, making it ideally suited for in-system programming.
The output voltage can be separately controlled down to 1.65V through the VCCQ
supply pin. This device can operate in the asynchronous or page read mode.
To increase the flexibility of the device, it contains an Erase Suspend and Program
Suspend feature. This feature will put the erase or program on hold for any amount of
time and let the user read data from or program data to any of the remaining sectors.
The end of a program or an erase cycle is detected by Data Polling or the toggle bit.
The VPP pin provides data protection and faster programming and erase times. When
the V
PP
input is below 0.8V, the program and erase functions are inhibited. When V
PP
is at 1.65V or above, normal program and erase operations can be performed. With
V
PP
at 12.0V, the program and erase operations are accelerated.
With V
PP
at 12V, a six-byte command (Enter Single Pulse Program Mode) to remove
the requirement of entering the three-byte program sequence is offered to further
improve programming time. After entering the six-byte code, only single pulses on the
write control lines are required for writing into the device. This mode (Single Pulse
Word Program) is exited by powering down the device, by taking the RESET pin to
GND or by a high-to-low transition on the V
PP
input. Erase, Erase Suspend/Resume,
Program Suspend/Resume and Read Reset commands will not work while in this
mode; if entered they will result in data being programmed into the device. It is not rec-
ommended that the six-byte code reside in the software of the final product but only
exist in external programming code.
Rev. 3366B鈥揊LASH鈥?/03
1