CY14C256PA CY14B256PA CY14E256PA 256-Kbit (32 K 8) SPI nvSRAM with Real Time Clock 256-Kbit (32 K 8) SPI nvSRAM with Real Time Clock Sleep mode Features Write protection 256-Kbit nonvolatile static random access memory (nvSRAM) Hardware protection using Write Protect (WP) pin Internally organized as 32 K 8 Software protection using Write Disable instruction STORE to QuantumTrap nonvolatile elements initiated Software block protection for 1/4, 1/2, or entire array automatically on power-down (AutoStore) or by using SPI Low power consumption instruction (Software STORE) or HSB pin (Hardware Average active current of 3 mA at 40 MHz operation STORE) Average standby mode current of 250 A RECALL to SRAM initiated on power-up (Power-Up Sleep mode current of 8 A RECALL) or by SPI instruction (Software RECALL) Automatic STORE on power-down with a small capacitor Industry standard configurations High reliability Operating voltages: = 2.4 V to 2.6 V Infinite read, write, and RECALL cycles CY14C256PA: V CC 1 million STORE cycles to QuantumTrap CY14B256PA: V = 2.7 V to 3.6 V CC = 4.5 V to 5.5 V Data retention: 20 years at 85C CY14E256PA: V CC Industrial temperature Real time clock (RTC) 16-pin small outline integrated circuit (SOIC) package Full-featured RTC Restriction of hazardous substances (RoHS) compliant Watchdog timer Clock alarm with programmable interrupts Overview Backup power fail indication Square wave output with programmable frequency (1 Hz, 1 The Cypress CY14X256PA combines a 256-Kbit nvSRAM with 512 Hz, 4096 Hz, 32.768 kHz) a full-featured RTC in a monolithic integrated circuit with serial Capacitor or battery backup for RTC SPI interface. The memory is organized as 32 K words of 8 bits Backup current of 0.45 A (typical) each. The embedded nonvolatile elements incorporate the 40 MHz and 104 MHz High-speed serial peripheral interface QuantumTrap technology, creating the worlds most reliable (SPI) nonvolatile memory. The SRAM provides infinite read and write 40 MHz clock rate SPI write and read with zero cycle delay cycles, while the QuantumTrap cells provide highly reliable 104 MHz clock rate SPI write and read (with special fast read nonvolatile storage of data. Data transfers from SRAM to the instructions) nonvolatile elements (STORE operation) takes place Supports SPI mode 0 (0,0) and mode 3 (1,1) automatically at power-down. On power-up, data is restored to SPI access to special functions the SRAM from the nonvolatile memory (RECALL operation). Nonvolatile STORE/RECALL You can also initiate the STORE and RECALL operations through SPI instruction. 8-byte serial number Manufacturer ID and Product ID For a complete list of related documentation, click here. V V V V Logic Block Diagram CC CAP RTCcap RTCbat Serial Number 8 x 8 Power Control Manufacturer ID / Block Product ID QuantumTrap 32 K x 8 SLEEP STORE SRAM RDSN/WRSN/RDID SI Memory 32 K x 8 RECALL Data & READ/WRITE CS SPI Control Logic Address STORE/RECALL/ASENB/ASDISB SCK Write Protection Control Instruction decoder WP SO RDRTC/WRTC WRSR/RDSR/WREN Status Register X in RTC Control Logic Registers INT/SQW Counters Xout Note 1. This device will be referred to as nvSRAM throughout the document. Cypress Semiconductor Corporation 198 Champion Court San Jose, CA 95134-1709 408-943-2600 Document Number: 001-65281 Rev. *J Revised February 1, 2018CY14C256PA CY14B256PA CY14E256PA Contents Pinout ................................................................................3 Device ID ......................................................................... 20 Pin Definitions ..................................................................3 RDID (Device ID Read) Instruction ........................... 20 Device Operation ..............................................................4 FAST RDID (Fast Device ID Read) Instruction ........ 21 SRAM Write .................................................................4 HOLD Pin Operation ................................................. 21 SRAM Read ................................................................4 Real Time Clock Operation ............................................ 22 STORE Operation .......................................................4 nvTIME Operation ..................................................... 22 AutoStore Operation ....................................................4 Clock Operations ....................................................... 22 Software STORE Operation ........................................5 Reading the Clock ..................................................... 22 Hardware STORE and HSB pin Operation .................5 Setting the Clock ....................................................... 22 RECALL Operation ......................................................5 Backup Power ........................................................... 22 Hardware RECALL (Power-Up) ..................................5 Stopping and Starting the Oscillator ..........................22 Software RECALL .......................................................5 Calibrating the Clock ................................................. 23 Disabling and Enabling AutoStore ...............................5 Alarm ......................................................................... 23 Serial Peripheral Interface ...............................................6 Watchdog Timer ........................................................ 23 SPI Overview ...............................................................6 Programmable Square Wave Generator ................... 24 SPI Modes .........................................................................7 Power Monitor ........................................................... 24 SPI Operating Features ....................................................8 Backup Power Monitor .............................................. 24 Power-Up ....................................................................8 Interrupts ................................................................... 24 Power Down ................................................................8 Interrupt Register ....................................................... 24 Active Power and Standby Power Modes ...................8 Flags Register ........................................................... 25 SPI Functional Description ..............................................9 RTC External Components ....................................... 26 Status Register ...............................................................10 PCB Design Considerations for RTC ............................ 27 Read Status Register (RDSR) Instruction .................10 Layout requirements .................................................. 27 Fast Read Status Register Maximum Ratings ........................................................... 32 (FAST RDSR) Instruction ................................................10 Operating Range ............................................................. 32 Write Status Register (WRSR) Instruction ................10 DC Electrical Characteristics ........................................ 32 Write Protection and Block Protection .........................11 Data Retention and Endurance ..................................... 33 Write Enable (WREN) Instruction ..............................11 Capacitance .................................................................... 33 Write Disable (WRDI) Instruction ..............................12 Thermal Resistance ........................................................ 33 Block Protection ........................................................12 AC Test Loads and Waveforms ..................................... 34 Hardware Write Protection (WP Pin) .........................12 AC Test Conditions ........................................................ 34 Memory Access ..............................................................12 RTC Characteristics ....................................................... 35 Read Sequence (READ) Instruction ..........................12 AC Switching Characteristics ....................................... 35 Fast Read Sequence Switching Waveforms .................................................... 36 (FAST READ) Instruction ................................................12 AutoStore or Power-Up RECALL ..................................37 Write Sequence (WRITE) Instruction ........................13 Switching Waveforms .................................................... 37 RTC Access .....................................................................15 Software Controlled STORE/RECALL Cycles .............. 38 READ RTC (RDRTC) Instruction ..............................15 Switching Waveforms .................................................... 38 Fast Read Sequence Hardware STORE Cycle ................................................. 39 (FAST RDRTC) Instruction ..............................................15 Ordering Information ...................................................... 40 WRITE RTC (WRTC) Instruction ...............................16 Ordering Code Definitions ......................................... 40 nvSRAM Special Instructions ........................................17 Package Diagram ............................................................ 41 Software STORE (STORE) Instruction .....................17 Acronyms ........................................................................ 42 Software RECALL (RECALL) Instruction ..................17 Document Conventions ................................................. 42 AutoStore Enable (ASENB) Instruction .....................17 Units of Measure ....................................................... 42 AutoStore Disable (ASDISB) Instruction ...................17 Document History Page ................................................. 43 Special Instructions .......................................................17 Sales, Solutions, and Legal Information ...................... 44 SLEEP Instruction .....................................................17 Worldwide Sales and Design Support ....................... 44 Serial Number .................................................................18 Products .................................................................... 44 WRSN (Serial Number Write) Instruction ..................18 PSoC Solutions ...................................................... 44 RDSN (Serial Number Read) Instruction ...................19 Cypress Developer Community ................................. 44 FAST RDSN Technical Support ..................................................... 44 (Fast Serial Number Read) Instruction .............................19 Document Number: 001-65281 Rev. *J Page 2 of 44