Cypress AutoStore STK14CA8 - Manual (Page 13)

STK14CA8
Document Number: 001-51592 Rev. ** Page 13 of 16
Low Average Active Power
CMOS technology provides the STK14CA8 with the benefit of
power supply current that scales with cycle time. Less current is
drawn as the memory cycle time becomes longer than 50 ns.
Figure 16 shows the relationship between I
CC
and
READ/WRITE cycle time. Worst case current consumption is
shown for commercial temperature range, V
CC
=3.6V, and chip
enable at maximum frequency. Only standby current is drawn
when the chip is disabled. The overall average current drawn by
the STK14CA8 depends on the following items:
1. The duty cycle of chip enable
2. The overall cycle rate for operations
3. The ratio of READs to WRITEs
4. The operating temperature
5. The VCC Level
6. I/O Loading
Figure 16. Current vs Cycle Time
Preventing AutoStore
The AutoStore function can be disabled by initiating an
AutoStore Disable sequence. A sequence of READ operations
is performed in a manner similar to the software STORE initi-
ation. To initiate the AutoStore Disable sequence, the following
sequence of E controlled or G controlled READ operations must
be performed:
The AutoStore can be re-enabled by initiating an AutoStore
Enable sequence. A sequence of READ operations is performed
in a manner similar to the software RECALL initiation. To initiate
the AutoStore Enable sequence, the following sequence of E
controlled or G controlled READ operations must be performed:
If the AutoStore function is disabled or re-enabled, a manual
STORE operation (Hardware or Software) must be issued to
save the AutoStore state through subsequent power down
cycles. The part comes from the factory with AutoStore enabled.
Read Address 0x4E38 Valid READ
Read Address 0xB1C7 Valid READ
Read Address 0x83E0 Valid READ
Read Address 0x7C1F Valid READ
Read Address 0x703F Valid READ
Read Address 0x8B45 AutoStore Disable
Read Address 0x4E38 Valid READ
Read Address 0xB1C7 Valid READ
Read Address 0x83E0 Valid READ
Read Address 0x7C1F Valid READ
Read Address 0x703F Valid READ
Read Address 0x4B46 AutoStore Enable
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