WE128K32-XXX
DATA POLLING CHARACTERISTICS
DATA POLLING
(VCC = 5.0V, VSS = 0V, TA = -55°C to +125°C)
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.
Parameter
Data Hold Time
Symbol
tDH
Min
10
Max
Unit
ns
OE# Hold Time
tOEH
tOE
10
ns
OE# To Output Valid
Write Recovery Time
55
ns
tWR
0
ns
FIGURE 8 – DATA POLLING WAVEFORMS
WE1-4#
CS1-4#
OE#
tOEH
tOE
tDH
I/O7
HIGH Z
tWR
ADDRESS
TOGGLE BIT CHARACTERISTICS(1)
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.
Symbol
tDH
Parameter
Data Hold Time
Min
10
Max
Units
ns
tOEH
OE# Hold Time
10
ns
tOE
OE# to Output Delay
OE# High Pulse
ns
tOEHP
tWR
150
0
ns
Write Recovery Time
ns
WE#
CS#
tOEH
OE#
tDH
tOE
HIGH Z
I/O6 (2)
tWR
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.
7
4315.19E-0718-ss-WE128K32-XXX
Mercury Corp. - Memory and Storage Solutions • (602) 437-1520 • www.mrcy.com
MERCURY [ MERCURY UNITED ELECTRONICS INC ]
