S71GS128NB0 SPANSION [SPANSION], S71GS128NB0 Datasheet - Page 114

• Manufacturer Part Number: S71GS128NB0
• Description: 128N based MCPs
• Manufacturer: SPANSION [SPANSION]

Note: Non-default BCR settings: Latency code two (three clocks); WAIT active LOW; WAIT asserted during delay.
Low-Power Operation
114
LB#/UB#
DQ[15:0]
A[22:0]
Standby Mode Operation
Temperature Compensated Refresh
ADV#
WAIT
WE#
CE#
OE#
CLK
V IH
V IL
V IH
V IL
V IH
V IL
V IH
V IL
V IH
V IL
V IH
V IL
V IH
V IL
V OH
V OL
V OH
V OL
During standby, the device current consumption is reduced to the level necessary
to perform the DRAM refresh operation. Standby operation occurs when CE# is
HIGH.
The device will enter a reduced power state upon completion of a READ or WRITE
operation, or when the address and control inputs remain static for an extended
period of time. This mode will continue until a change occurs to the address or
control inputs.
Temperature compensated refresh (TCR) is used to adjust the refresh rate de-
pending on the device operating temperature. DRAM technology requires
increasingly frequent refresh operation to maintain data integrity as tempera-
tures increase. More frequent refresh is required due to increased leakage of the
DRAM capacitive storage elements as temperatures rise. A decreased refresh rate
at lower temperatures will facilitate a savings in standby current.
TCR allows for adequate refresh at four different temperature thresholds (+15
+45
higher than the case temperature of the CellularRAM device. For example, if the
case temperature is 50
sumption by selecting the +7
result in inadequate refreshing and cause data corruption.
High-Z
°
C, +70
Additional WAIT states inserted to allow refresh completion.
Address
Valid
Figure 30. Refresh Collision During WRITE Operation
°
C, and +85
°
C, the system can minimize self refresh current con-
°
C). The setting selected must be for a temperature
A d v a n c e
°
0C setting. The +15
CellularRAM Type 2
I n f o r m a t i o n
°
C and +45
D[0]
D[1]
°
C settings would
D[2]
Legend:
cellRAM_00_A0 October 4, 2004
°
D[3]
C,
Don't care