Cypress CY14B256K manual RTC Characteristics, Truth Table For Sram Operations

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CY14B256K

RTC Characteristics

Parameter	Description	Test Conditions		Min	Max	Unit
IBAK [25]	RTC Backup Current		Commercial		300	nA
			Industrial		350	nA

VRTCbat [26]	RTC Battery Pin Voltage			1.8	3.3	V
VRTCcap [27]	RTC Capacitor Pin Voltage			1.2	2.7	V
tOCS	RTC Oscillator Time to Start	At Min Temperature from Power up or Enable			10	sec

		At 25°C Temperature from Power up or Enable			5	sec

Truth Table For SRAM Operations

HSB should remain HIGH for SRAM Operations.

CE	WE	OE	Inputs and Outputs	Mode	Power
H	X	X	High Z	Deselect/Power down	Standby
L	H	L	Data Out (DQ0–DQ7);	Read	Active
L	H	H	High Z	Output Disabled	Active
L	L	X	Data in (DQ0–DQ7);	Write	Active

Notes

25.From either VRTCcap or VRTCbat.

26.Typical = 3.0V during normal operation.

27.Typical = 2.4V during normal operation.

Document Number: 001-06431 Rev. *H

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Contents Functional Description FeaturesLogic Block Diagram Cypress Semiconductor Corporation 198 Champion CourtPin Configurations Pin DefinitionsAutoStore Operation Device OperationHardware Store HSB Operation Software Recall Hardware Recall Power UpSoftware Store Data ProtectionLow Average Active Power Best Practices Current versus Cycle TimeMode Selection A13-A0 Power Real Time Clock Operation Watchdog Timer AlarmCalibrating the Clock Interrupt Register Power MonitorInterrupts Flags RegisterInterrupt Block Diagram RTC Register Map5 BCD Format Data Function/Range WDF OscfDate Time Keeping Hours 0x7FFB Register Map Detail Time Keeping Years 0x7FFF 10s YearsTime Keeping Months 0x7FFE 10s Month Time Keeping Minutes 0x7FFA0x7FF7 Alarm Day 0x7FF5Register Map Detail Calibration/Control 0X7FF8 Interrupt Status/Control 0x7FF6Alarm Seconds 0x7FF2 Register Map Detail Alarm Hours 0x7FF4 10s Alarm HoursTo ignore the hours value Alarm Minutes 0x7FF3 When the Flags register is read or on power-upOperating Range DC Electrical CharacteristicsMaximum Ratings RangeThermal Resistance Data Retention and EnduranceCapacitance AC Test ConditionsAC Switching Characteristics Parameter Sram Read CycleParameter Cypress Alt Description 25 ns 35 ns 45 ns Min Max Unit Sram Write CycleAutoStore or Power Up Recall Parameter Description CY14B256K Unit Min MaxSoftware Controlled STORE/RECALL Cycles 20 Parameter Alt Description 25 ns 35 ns 45 ns Unit Min MaxSoft Sequence Commands Hardware Store CycleInputs and Outputs Mode Power RTC CharacteristicsTruth Table For Sram Operations Part Numbering Nomenclature CY 14 B 256 K SP 25 X C T Ordering Information Package Diagrams Pin Shrunk Small Outline PackageDocument History Orig. of Change Submission Description of Change DateStarting the Oscillator and Alarm descriptions under RTC Updated Features sectionUpdated Reading the clock, Backup Power, Stopping Added default values to RTC Register Map tableWorldwide Sales and Design Support Products PSoC Solutions Sales, Solutions, and Legal InformationUSB