CY14C256PA Datasheet, PDF (3/44 Pages) Cypress Semiconductor – 256-Kbit (32 K x 8) SPI nvSRAM with Real Time Clock Infinite read, write, and RECALL cycles

CY14C256PA
CY14B256PA
CY14E256PA
Pinout
Figure 1. Pin Diagram - 16-pin SOIC
NC 1
VRTCbat ₂
Xout ₃
Xin ₄
WP 5
HOLD 6
V_{RTCcap 7}
V_SS
8
16 V_CC
15 INT/SQW
14
Top View ₁₃
not to scale
12
V_CAP
SO
SI
11 SCK
10 CS
9 HSB
Pin Definitions
Pin Name
CS
SCK
SI
SO
WP
HOLD
HSB
V_CAP
V_RTCcap
V_RTCbat
Xout
Xin
INT/SQW
NC
V_SS
V_CC
I/O Type
Input
Input
Input
Output
Input
Input
Input/Output
Power supply
Power supply
Power supply
Output
Input
Output
No connect
Power supply
Power supply
Description
Chip select: Activates the device when pulled LOW. Driving this pin HIGH puts the device in low
power standby mode.
Serial clock: Runs at speeds up to a maximum of f_SCK. Serial input is latched at the rising edge of
this clock. Serial output is driven at the falling edge of the clock.
Serial input: Pin for input of all SPI instructions and data.
Serial output: Pin for output of data through SPI.
Write Protect: Implements hardware write protection in SPI.
HOLD pin: Suspends Serial Operation.
Hardware STORE Busy: Output: Indicates busy status of nvSRAM when LOW. After each
Hardware and Software STORE operation HSB is driven HIGH for a short time (t_HHHD) with
standard output high current and then a weak internal pull-up resistor keeps this pin HIGH (external
pull-up resistor connection optional).
Input: Hardware STORE implemented by pulling this pin LOW externally.
AutoStore capacitor. Supplies power to the nvSRAM during power loss to STORE data from the
SRAM to nonvolatile elements. If AutoStore is not needed, this pin must be left as No Connect. It
must never be connected to ground.
Capacitor backup for RTC: Left unconnected if V_RTCbat is used.
Battery backup for RTC: Left unconnected if V_RTCcap is used.
Crystal output connection
Crystal input connection
Interrupt output/calibration/square wave. Programmable to respond to the clock alarm, the
watchdog timer, and the power monitor. Also programmable to either active HIGH (push or pull) or
LOW (open drain). In calibration mode, a 512 Hz square wave is driven out. In the square wave
mode, you may select a frequency of 1 Hz, 512 Hz, 4,096 Hz, or 32,768 Hz to be used as a
continuous output.
No connect. This pin is not connected to the die.
Ground
Power supply
Document #: 001-65281 Rev. *B
Page 3 of 44
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