Cypress CY14B256K manual Interrupt Block Diagram

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Watchdog

WDF

CY14B256K

Figure 5. Interrupt Block Diagram

Timer

Power

Monitor

VINT

Clock Alarm

WIE

PFE

AIE

	P/L		VCC

Pin Driver

H/L VSS

	WDF - Watchdog Timer Flag
	WIE - Watchdog Interrupt
	Enable
	PF - Power Fail Flag
INT	PFE - Power Fail Enable
	AF - Alarm Flag
	AIE - Alarm Interrupt Enable
	P/L - Pulse Level
	H/L - High/Low

Figure 6. RTC Recommended Component Configuration

1
C	Y
RF	Y
	1
2
C

DQ 0

A2 A1

Recommended Values:

Y1 = 32.768KHz

RF = 10M Ohm

C1 = 0 (install cap footprint, but leave unloaded)

C2 = 56 pF + 10% (do not vary from this value)

Note

4.Schottky diodes, (VF < 0.4V with IF at 100mA) are recommended at pins A0 - A3 and DQ0 in applications where undershoot exceeds -0.5V. Please see application note AN49947 for further details.

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