FM20L08_07 RAMTRON [Ramtron International Corporation], FM20L08_07 Datasheet - Page 7

• Manufacturer Part Number: FM20L08_07
• Description: 1Mbit Bytewide FRAM Memory - Industrial Temp.
• Manufacturer: RAMTRON [Ramtron International Corporation]

Software Write Protect Timing (-TG1 only)
SRAM Drop-In Replacement
The FM20L08 has been designed to be a drop-in
replacement for standard asynchronous SRAMs. The
device does not require /CE to toggle for each new
address. /CE may remain low indefinitely while V
is applied. When /CE is low, the device automatically
detects address changes and a new access is begun. It
also allows page mode operation at speeds up to
33MHz.
Although /CE may be held low for extended
periods of time, the pin should not be tied to
ground or held low during power cycles.
must be pulled high and allowed to track V
during powerup and powerdown cycles. It is the
user’s responsibility to ensure that chip enable is
high to prevent incorrect operation.
shows a pullup resistor on /CE which will keep the
pin high during power cycles assuming the
MCU/MPU
condition. The pullup resistor value should be
chosen to ensure the /CE pin tracks V
enough value that the current drawn when /CE is
low is not an issue.
Rev. 1.72
May 2007
DQ(7:0)
A(16:0)
WE
CE
OE
pin
05555
tri-states during
1AAAA
03333
DD
the reset
yet a high
Figure 3
1CCCC
/CE
DD
DD
100FF
For applications that require the lowest power
consumption, the /CE signal should be active only
during memory accesses. Due to the external pullup
resistor, some supply current will be drawn while /CE
is low. When /CE is high, the device draws no more
than the maximum standby current I
The FM20L08 is backward compatible with the
256Kbit FM18L08 device.
FM20L08 with /CE toggling low on every address is
perfectly acceptable.
0FF00
MCU/
Figure 3. Use of Pullup Resistor on /CE
MPU
1AAAA
Data
1CCCC
FM20L08 - Industrial Temp.
Data
V
R
DD
0FF00
So, operating the
SB
.
FM20L08
00000
CE
WE
OE
A(16:0)
DQ
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