Rainbow Electronics AT28C64X - Manual (Page 2)

AT28C64(X)
2
The AT28C64 is accessed like a Static RAM for the read or
write cycles without the need for external components. Dur-
ing a byte write, the address and data are latched inter-
nally, freeing the microprocessor address and data bus for
other operations. Following the initiation of a write cycle,
the device will go to a busy state and automatically clear
and write the latched data using an internal control timer.
The device includes two methods for detecting the end of a
write cycle, level detection of RDY/BUSY (unless pin 1 is
N.C.) and DATA Polling of I/O
7
. Once the end of a write
cycle has been detected, a new access for a read or write
can begin.
The CMOS technology offers fast access times of 120 ns at
low power dissipation. When the chip is deselected the
standby current is less than 100
µA.
Atmel’s AT28C64 has additional features to ensure high
quality and manufacturability. The device utilizes error cor-
rection internally for extended endurance and for improved
data retention characteristics. An extra 32 bytes of
EEPROM are available for device identification or tracking.
Block Diagram
Absolute Maximum Ratings*
Temperature under Bias ................................ -55°C to +125°C *NOTICE: Stresses beyond those listed under “Absolute
Maximum Ratings” may cause permanent dam-
age to the device. This is a stress rating only and
functional operation of the device at these or any
other conditions beyond those indicated in the
operational sections of this specification is not
implied. Exposure to absolute maximum rating
conditions for extended periods may affect
device reliability
Storage Temperature ..................................... -65°C to +150°C
All Input Voltages (including NC Pins)
with Respect to Ground ...................................-0.6V to +6.25V
All Output Voltages
with Respect to Ground .............................-0.6V to V
CC
+ 0.6V
Voltage on OE and A9
with Respect to Ground ...................................-0.6V to +13.5V