Specifications
CY14C101PA
CY14B101PA
CY14E101PA
Document Number: 001-54392 Rev. *N Page 8 of 44
SPI Operating Features
Power-Up
Power-up is defined as the condition when the power supply is
turned on and V
CC
crosses V
switch
voltage.
As described earlier, at power-up nvSRAM performs a Power-Up
RECALL operation for t
FA
duration during which, all memory
accesses are disabled. The HSB
pin can be probed to check the
Ready/Busy status of nvSRAM after power-up.
The following are the device status after power-up:
■ Selected (Active power mode) if CS pin is LOW
■ Deselected (Standby power mode) if CS pin is HIGH
■ Not in the Hold condition
■ Status Register state:
❐ Write Enable (WEN) bit is reset to ‘0’.
❐ WPEN, BP1, BP0 unchanged from previous STORE
operation
The WPEN, BP1, and BP0 bits of the Status Register are
nonvolatile bits and remain unchanged from the previous
STORE operation.
Power-Down
At power-down (continuous decay of V
CC
), when V
CC
drops from
the normal operating voltage and below the V
SWITCH
threshold
voltage, the device stops responding to any instruction sent to it.
If a write cycle is in progress and the last data bit D0 has been
received when the power goes down, it is allowed t
DELAY
time to
complete the write. After this, all memory accesses are inhibited
and a conditional AutoStore operation is performed (AutoStore is
not performed if no writes have happened since the last RECALL
cycle). This feature prevents inadvertent writes to nvSRAM from
happening during power-down. However, to avoid the possibility
of inadvertent writes during power-down, ensure that the device
is deselected and is in standby power mode and the CS
follows
the voltage applied on V
CC
.
Active Power and Standby Power Modes
When CS is LOW, the device is selected and is in the active
power mode. The device consumes I
CC
current, as specified in
DC Electrical Characteristics on page 31. When CS
is HIGH, the
device is deselected and the device goes into the standby power
mode after t
SB
time
if a STORE or RECALL cycle is not in
progress. If a STORE/RECALL cycle is in progress, the device
goes into the standby power mode after the STORE/RECALL
cycle is completed. In the standby power mode the current drawn
by the device drops to I
SB
.