Specifications

CY14C101PA
CY14B101PA
CY14E101PA
Document Number: 001-54392 Rev. *N Page 5 of 44
to complete the Store. This corrupts the data stored in nvSRAM,
Status Register, and the serial number, and it unlocks the SNL
bit. To resume normal functionality, the WRSR instruction must
be issued to update the nonvolatile bits BP0, BP1, and WPEN in
the Status Register.
Figure 2 shows the proper connection of the storage capacitor
(V
CAP
) for AutoStore operation. Refer to DC Electrical
Characteristics on page 31 for the size of the V
CAP
.
Figure 2. AutoStore Mode
Software STORE Operation
Software STORE allows the user to trigger a STORE operation
through a special SPI instruction. STORE operation is initiated
by executing a STORE instruction regardless of whether or not
a write has been performed since the last NV operation.
A STORE cycle takes t
STORE
time to complete, during which all
the memory accesses to nvSRAM are inhibited. The RDY
bit of
the Status Register or the HSB
pin may be polled to find the
Ready/Busy status of the nvSRAM. After the t
STORE
cycle time
is completed, the SRAM is activated again for read and write
operations.
Hardware STORE and HSB pin Operation
The HSB pin in CY14X101PA is used to control and
acknowledge STORE operations. If no STORE/RECALL is in
progress, this pin can be used to request a Hardware STORE
cycle. When the HSB
pin is driven LOW, the CY14X101PA
conditionally initiates a STORE operation after t
DELAY
duration.
A STORE cycle starts only if a write to the SRAM has been
performed since the last STORE or RECALL cycle. Reads and
Writes to the memory are inhibited for t
STORE
duration or as long
as HSB
pin is LOW. The HSB pin also acts as an open drain
driver (internal 100 k weak pull up resistor) that is internally
driven LOW to indicate a busy condition when the STORE
(initiated by any means) is in progress.
Note After each Hardware and Software STORE operation, HSB
is driven HIGH for a short time (t
HHHD
) with standard output high
current and then remains HIGH by an internal 100 k pull-up
resistor.
Note For successful last data byte STORE, a hardware STORE
should be initiated at least one clock cycle after the last data bit
D0 is received.
Upon completion of the STORE operation, the nvSRAM memory
access is inhibited for t
LZHSB
time after HSB pin returns HIGH.
The HSB
pin must be left unconnected if not used.
RECALL Operation
A RECALL operation transfers the data stored in the nonvolatile
QuantumTrap elements to the SRAM. In CY14X101PA, a
RECALL may be initiated in two ways: Hardware RECALL,
initiated on power-up and Software RECALL, initiated by a SPI
RECALL instruction.
Internally, RECALL is a two step procedure. First, the SRAM data
is cleared. Next, the nonvolatile information is transferred into the
SRAM cells. All memory accesses are inhibited while a RECALL
cycle is in progress. The RECALL operation does not alter the
data in the nonvolatile elements.
Hardware RECALL (Power-Up)
During power-up, when V
CC
crosses V
SWITCH
, an automatic
RECALL sequence is initiated, which transfers the content of
nonvolatile memory on to the SRAM. The data would have been
previously stored on the nonvolatile memory through a STORE
sequence.
A Power-Up RECALL cycle takes t
FA
time to complete and the
memory access is disabled during this time. The HSB
pin is used
to detect the Ready status of the device.
Software RECALL
Software RECALL allows you to initiate a RECALL operation to
restore the content of nonvolatile memory on to the SRAM. In
CY14X101PA, this can be done by issuing a RECALL instruction
in SPI.
A Software RECALL takes t
RECALL
time to complete during
which all memory accesses to nvSRAM are inhibited. The
controller must provide sufficient delay for the RECALL operation
to complete before issuing any memory access instructions.
Disabling and Enabling AutoStore
If the application does not require the AutoStore feature, it can
be disabled in CY14X101PA by using the ASDISB instruction. If
this is done, the nvSRAM does not perform a STORE operation
at power-down.
AutoStore can be re-enabled by using the ASENB instruction.
However, these operations are not nonvolatile and if you need
this setting to survive the power cycle, a STORE operation must
be performed following AutoStore Disable or Enable operation.
Note CY14X101PA comes from the factory with AutoStore
Enabled.
Note If AutoStore is disabled and V
CAP
is not required, then the
V
CAP
pin must be left open. The V
CAP
pin must never be
connected to ground. The Power Up RECALL operation cannot
be disabled in any case.
0.1uF
V
CC
10kOhm
V
CAP
CS
V
CAP
V
SS
V
CC