PRELIMINARY
CY14B256L
Document #: 001-06422 Rev. *E
Page 6 of 17
Preventing AutoStore
Disable the AutoStore function 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 CE-controlled READ operations must
be performed:
1. Read address 0x0E38 valid READ
2. Read address 0x31C7 valid READ
3. Read address 0x03E0 valid READ
4. Read address 0x3C1F valid READ
5. Read address 0x303F valid READ
6. Read address 0x03F8 AutoStore Disable
Re-enable the AutoStore 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
CE-controlled READ operations must be performed:
1. Read address 0x0E38 valid READ
2. Read address 0x31C7 valid READ
3. Read address 0x03E0 valid READ
4. Read address 0x3C1F valid READ
5. Read address 0x303F valid READ
6. Read address 0x07F0 AutoStore Enable
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.
Noise Considerations
The CY14B256L is a high speed memory and so must have a
high frequency bypass capacitor of approximately 0.1 µF
connected between VCC and VSS, using leads and traces that
are as short as possible. As with all high speed CMOS ICs,
careful routing of power, ground, and signals reduces circuit
noise.
Low Average Active Power
CMOS technology provides the CY14B256L the benefit of
drawing less current when it is cycled at times longer than
50 ns. Figure 2 shows the relationship between ICC and
READ/WRITE cycle time. Worst-case current consumption is
shown for commercial temperature range, VCC = 3.45V, and
chip enable at maximum frequency. Only standby current is
drawn when the chip is disabled. The overall average current
drawn by the CY14B256L depends on the following items:
• The duty cycle of chip enable.
• The overall cycle rate for accesses.
• The ratio of READs to WRITEs.
• The operating temperature.
•The VCC level.
• IO loading.
Figure 2. Current vs. Cycle Time
[+] Feedback
[+] Feedback
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
