CY14C256I_12 Datasheet, PDF (1/40 Pages) Cypress Semiconductor – 256-Kbit (32 K × 8) Serial (I2C) nvSRAM with Real Time Clock

CY14C256I
CY14B256I
CY14E256I
256-Kbit (32 K × 8) Serial (I²C) nvSRAM
with Real Time Clock
256-Kbit (32 K × 8) Serial (I2C) nvSRAM with Real Time Clock
Features
■ 256-Kbit nonvolatile static random access memory (nvSRAM)
❐ Internally organized as 32 K × 8
❐ STORE to QuantumTrap nonvolatile elements initiated
automatically on power-down (AutoStore) or by using I²C
command (Software STORE) or HSB pin (Hardware STORE)
❐
RECALL
RECALL)
to
or
SRAM initiated on power-up (Power-Up
by I²C command (Software RECALL)
❐ Automatic STORE on power-down with a small capacitor
■ High reliability
❐ Infinite read, write, and RECALL cycles
❐ 1 million STORE cycles to QuantumTrap
❐ Data retention: 20 years at 85 °C
■ Real Time Clock (RTC)
❐ Full-featured RTC
❐ Watchdog timer
❐ Clock alarm with programmable interrupts
❐ Backup power fail indication
❐ Square wave output with programmable frequency (1 Hz,
512 Hz, 4096 Hz, 32.768 kHz)
❐ Capacitor or battery backup for RTC
❐ Backup current of 0.45 µA (typical)
■ High-speed I²C interface
❐ Industry standard 100 kHz and 400 kHz speed
❐ Fast mode Plus 1 MHz speed
❐ High speed: 3.4 MHz
❐ Zero cycle delay reads and writes
■ Write protection
❐ Hardware protection using Write Protect (WP) pin
❐ Software block protection for one-quarter, one-half, or entire
array
■ I²C access to special functions
❐ Nonvolatile STORE/RECALL
❐ 8-byte serial number
❐ Manufacturer ID and Product ID
❐ Sleep mode
■ Low power consumption
❐ Average active current of 1 mA at 3.4 MHz operation
❐ Average standby mode current of 250 µA
❐ Sleep mode current of 8 µA
■ Industry standard configurations
❐ Operating voltages:
• CY14C256I: V_CC = 2.4 V to 2.6 V
• CY14B256I: V_CC = 2.7 V to 3.6 V
• CY14E256I: V_CC = 4.5 V to 5.5 V
❐ Industrial temperature
❐ 16-pin small outline integrated circuit (SOIC) package
❐ Restriction of hazardous substances (RoHS) compliant
Overview
The Cypress CY14C256I/CY14B256I/CY14E256I combines a
256-Kbit nvSRAM^[1] with a full-featured RTC in a monolithic
integrated circuit with serial I²C interface. The memory is
organized as 64 K words of 8 bits each. The embedded
nonvolatile elements incorporate the QuantumTrap technology,
creating the world’s most reliable nonvolatile memory. The
SRAM provides infinite read and write cycles, while the
QuantumTrap cells provide highly reliable nonvolatile storage of
data. Data transfers from SRAM to the nonvolatile elements
(STORE operation) takes place automatically at power-down.
On power-up, data is restored to the SRAM from the nonvolatile
memory (RECALL operation). The STORE and RECALL
operations can also be initiated by the user through I²C
commands.
Logic Block Diagram
VCC VCAP VRTCcap V_RTCbat
Power Control
Block
Sleep
Serial Number
8x8
Manufacturer ID /
Product ID
Memory Control Register
Command Register
SDA
SCL
A2, A1, A0
WP
2
I C Control Logic
Slave Address
Decoder
Control Registers Slave
Memory Slave
RTC Slave
Memory
Address and Data
Control
QuantumTrap
32 K x 8
SRAM
32 K x 8
STORE
RECALL
X in
INT/SQW
Xout
RTC Control Logic
Registers
Counters
Note
1. Serial (I²C) nvSRAM will be referred to as nvSRAM throughout the datasheet.
Cypress Semiconductor Corporation • 198 Champion Court
Document Number: 001-65230 Rev. *D
• San Jose, CA 95134-1709 • 408-943-2600
Revised July 25, 2012