WE512K8, WE256K8,
WE128K8-XCX
PAGE WRITE OPERATION
These devices have a page write operation that allows one to 64
bytes of data (one to 128 bytes for the WE512K8) to be written
into the device and then simultaneously written during the internal
programming period. Successive bytes may be loaded in the same
manner after the first data byte has been loaded. An internal timer
begins a time out operation at each write cycle. If another write cycle
is completed within 150μs or less, a new time out period begins.
Each write cycle restarts the delay period. The write cycles can be
continued as long as the interval is less than the time out period.
The page address must be the same for each byte load and must
be valid during each high to low transition of WE# (or CS#). The
block address also must be the same for each byte load and must
remain valid throughout the WE# (or CS#) low pulse. The page
and block address lines are summarized below:
PAGE MODE CHARACTERISTICS
VCC = 5.0V, VSS = 0V, -55°C ≤ TA ≤ +125°C
The usual procedure is to increment the least significant address
lines from A0 through A5 (A0 through A6 for the WE512K8) at each
write cycle. In this manner a page of up to 64 bytes (128 bytes for
the WE512K8) can be loaded into the EEPROM in a burst mode
before beginning the relatively long interval programming cycle.
Parameter
Write Cycle Time, TYP = 6mS
Data Set-up Time
Symbol
tWC
Min
Max
Unit
ms
ns
10
tDS
100
10
Data Hold Time
tDH
ns
Write Pulse Width
tWP
150
ns
After the 150μs time out is completed, the EEPROM begins an
internal write cycle. During this cycle the entire page of bytes will
be written at the same time. The internal programming cycle is the
same regardless of the number of bytes accessed.
Byte Load Cycle Time
Write Pulse Width High
tBLC
tWPH
150
μs
ns
50
Device
Block Address
A17-A18
Page Address
A7-A16
WE512K8-XCX
WE256K8-XCX
WE128K8-XCX
A15-A17
A6-A14
A15-A16
A6-A14
FIGURE 9 – PAGE WRITE WAVEFORMS
OE#
CS#
WE#
ADDRESS (1)
DATA
NOTE:
1. Decoded Address Lines must be valid for the duration of the write.
Microsemi Corporation reserves the right to change products or specifications without notice.
August 2011 © 2011 Microsemi Corporation. All rights reserved.
Rev. 4
9
Microsemi Corporation • (602) 437-1520 • www.microsemi.com
MERCURY [ MERCURY UNITED ELECTRONICS INC ]
