WME128K8-XXX
DATA POLLING CHARACTERISTICS
DATA POLLING
VCC = 5.0V, VSS = 0V, -55°C ≤ TA ≤ +125°C
The WME128K8-XXX offers a data polling feature which allows a
faster method of writing to the device. Figure 6 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 I/O7. 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
Symbol
tdh
Min
10
Max
Unit
ns
Data Hold Time
OE# Hold Time
OE# To Output Valid
Write Recovery Time
toeh
toe
10
ns
55
ns
twr
0
ns
FIGURE 6 – DATA POLLING WAVEFORMS
WE#
CS#
OE#
tOEH
tOE
tDH
I/O7
HIGH Z
tWR
ADDRESS
TOGGLE BUT 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
Min
10
Max
Units
ns
Data Hold Time
OE Hold Time
tOEH
tOE
tOEHP
tWR
10
ns
OE to Output Delay
OE High Pulse
Write Recovery Time
ns
150
0
ns
ns
WE#
CS#
tOEH
OE#
tOE
tDH
HIGH Z
(2)
I/O6
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.
6
4311.11E-0718-ss-WME128K8-XXX
Mercury Corp. - Memory and Storage Solutions • (602) 437-1520 • www.mrcy.com