AT28BV64-30 ATMEL Corporation, AT28BV64-30 Datasheet - Page 3

• Manufacturer Part Number: AT28BV64-30
• Description: 64K 8K x 8 Battery-Voltage CMOS E2PROM
• Manufacturer: ATMEL Corporation

Device Operation
READ:
When CE and OE are low and WE is high, the data stored
at the memory location determined by the address pins is
asserted on the outputs. The outputs are put in a high im-
pedance state whenever CE or OE is high. This dual line
control gives designers increased flexibility in preventing
bus contention.
BYTE WRITE:
to writing into a Static RAM. A low pulse on the WE or CE
input with OE high and CE or WE low (respectively) initi-
ates a byte write. The address location is latched on the
falling edge of WE (or CE); the new data is latched on the
rising edge. Internally, the device performs a self-clear be-
fore write. Once a byte write has been started, it will auto-
matically time itself to completion. Once a programming
operation has been initiated and for the duration of t
read operation will effectively be a polling operation.
READY/BUSY:
output that can be used to detect the end of a write cycle.
RDY/BUSY is actively pulled low during the write cycle
and is released at the completion of the write. The open
drain connection allows for OR-tying of several devices to
the same RDY/BUSY line.
The AT28BV64 is accessed like a Static RAM.
Writing data into the AT28BV64 is similar
Pin 1 is an open drain READY/BUSY
WC
, a
DATA POLLING:
POLLING to signal the completion of a write cycle. During
a write cycle, an attempted read of the data being written
results in the complement of that data for I/O
outputs are indeterminate). When the write cycle is fin-
ished, true data appears on all outputs.
WRITE PROTECTION:
are protected against in the following ways. (a) V
sense— if V
inhibited. (b) V
reached 2.0V the device will automatically time out 10 ms
(typical) before allowing a byte write. (c) Write Inhibit—
holding any one of OE low, CE high or WE high inhibits
byte write cycles.
CC
is below 1.8V (typical) the write function is
CC
power on delay— once V
The AT28BV64 provides DATA
AT28BV64
Inadvertent writes to the device
7
(the other
CC
2-129
h a s
CC