STK11C88-3
Internally, RECALL is a two-step procedure. First,
the SRAM data is cleared, and second, the nonvola-
tile information is transferred into the SRAM cells.
After the tRECALL cycle time the SRAM will once again
be ready for READ and WRITE operations. The
RECALL operation in no way alters the data in the
Nonvolatile Elements. The nonvolatile data can be
recalled an unlimited number of times.
HARDWARE PROTECT
The STK11C88-3 offers hardware protection
against inadvertent STORE operation during low-
voltage conditions. When VCC < VSWITCH, all software
STORE operations are inhibited.
LOW AVERAGE ACTIVE POWER
The STK11C88-3 draws significantly less current
when it is cycled at times longer than 55ns. Figure 2
shows the relationship between ICC and READ cycle
time. Worst-case current consumption is shown for
both CMOS and TTL input levels (commercial tem-
perature range, VCC = 3.6V, 100% duty cycle on
chip enable). Figure 3 shows the same relationship
for WRITE cycles.If the chip enable duty cycle is less
than 100%, only standby current is drawn when the
chip is disabled. The overall average current drawn
by the STK11C88-3 depends on the following
items: 1) CMOS vs. TTL input levels; 2) the duty
cycle of chip enable; 3) the overall cycle rate for
accesses; 4) the ratio of READs to WRITEs; 5) the
POWER-UP RECALL
During power up, or after any low-power condition
(VCC < VRESET ), an internal RECALL request will be
latched. When VCC once again exceeds the sense
voltage of VSWITCH, a RECALL cycle will automatically
be initiated and will take tRESTORE to complete.
If the STK11C88-3 is in a WRITE state at the end of
power-up RECALL, the SRAM data will be corrupted.
To help avoid this situation, a 10K Ohm resistor
should be connected either between W and system
VCC or between E and system VCC.
operating temperature; 6) the V level; and 7) I/O
CC
loading.
50
40
30
20
50
40
30
TTL
CMOS
20
TTL
10
0
10
CMOS
150 200
0
50
100
Cycle Time (ns)
50
100
150
200
Cycle Time (ns)
Figure 2: I (max) Reads
Figure 3: I (max) Writes
CC
CC
March 2006
8
Document Control # ML0013 rev 0.2
SIMTEK [ SIMTEK CORPORATION ]
