we128k32-xxx White Electronic Designs Corporation, we128k32-xxx Datasheet - Page 7

• Manufacturer Part Number: we128k32-xxx
• Description: 128kx32 Eeprom Module, 5962-94585
• Manufacturer: White Electronic Designs Corporation

DATA POLLING
The WE128K32-XXX offers a data polling feature which
allows a faster method of writing to the device. Figure 8
shows the timing diagram for this function. During a byte
or page write cycle, an attempted read of the last byte
written will result in the complement of the written data
on D7 (for each chip.) Once the write cycle has been
completed, true data is valid on all outputs and the next
cycle may begin. Data polling may begin at any time during
the write cycle.
TOGGLE BIT: In addition to DATA# Polling another method for determining the end of
a write cycle is provided. During the write operation, successive attempts to read data
from the device will result in I/O6 toggling between one and zero. Once the write has
completed, I/O6 will stop toggling and valid data will be read. Reading the toggle bit may
begin at any time during the write cycle.
NOTE:
1. Toggling either OE# or CS# or both OE# and CS# will operate toggle bit.
2. Beginning and ending state of I/O6 will vary
3. Any address location may be used but the address should not vary.
White Electronic Designs Corp. reserves the right to change products or specifi cations without notice.
March 2006
Rev. 10
White Electronic Designs
WE#
OE#
CS#
I/O6
ADDRESS
(2)
WE
CS
OE
1-4
1-4
I/O
FIGURE 8 – DATA POLLING WAVEFORMS
#
#
#
7
t
DH
t
t
DH
OEH
t
OE
t
OEH
t
OE
HIGH Z
HIGH Z
7
Parameter
Data Hold Time
OE# Hold Time
OE# To Output Valid
Write Recovery Time
Symbol
t
tWR
t
OEHP
t
OEH
t
DH
OE
DATA POLLING CHARACTERISTICS
TOGGLE BUT CHARACTERISTICS
White Electronic Designs Corporation • [phone] • www.wedc.com
Parameter
Data Hold Time
OE# Hold Time
OE# to Output Delay
OE# High Pulse
Write Recovery Time
(V
CC
= 5.0V, V
t
WR
SS
t
WR
= 0V, T
Symbol
tOEH
tWR
tDH
tOE
WE128K32-XXX
A
= -55°C to +125°C)
Min
150
10
10
0
Min
10
10
0
Max
Max
55
(1)
Units
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns