Cypress CY14B256K manual Parameter Cypress Alt

Page 18

CY14B256K

AC Switching Characteristics (continued)

Parameter

Cypress	Alt.
Parameter	Parameter

Description

25 ns		35 ns		45 ns
Min	Max	Min	Max	Min	Max

Unit

SRAM Write Cycle

tWC	tAVAV	Write Cycle Time	25		35		45		ns
tPWE	tWLWH, tWLEH	Write Pulse Width	20		25		30		ns
tSCE	tELWH, tELEH	Chip Enable To End of Write	20		25		30		ns
tSD	tDVWH, tDVEH	Data Setup to End of Write	10		12		15		ns
tHD	tWHDX, tEHDX	Data Hold After End of Write	0		0		0		ns
tAW	tAVWH, tAVEH	Address Setup to End of Write	20		25		30		ns
tSA	tAVWL, tAVEL	Address Setup to Start of Write	0		0		0		ns
tHA	tWHAX, tEHAX	Address Hold After End of Write	0		0		0		ns
tHZWE [12, 15]	tWLQZ	Write Enable to Output Disable		10		13		15	ns
tLZWE [12]	tWHQX	Output Active After End of Write	3		3		3		ns

Figure 10. SRAM Write Cycle 1: WE Controlled [14, 16]

	tWC
ADDRESS
	tSCE
CE
	tAW
	tSA
WE	tPWE
WE
	tSD
DATA IN	DATA VALID
	tHZWE
	HIGH IMPEDANCE

DATA OUT

PREVIOUS DATA

tHA

tHD

tLZWE

Figure 11. SRAM Write Cycle 2: CE Controlled

ADDRESS

CE

WE

DATA IN

DATA OUT

tSA

tWC

tSCE				tHA

tAW

tPWE

tSD tHD

DATA VALID

HIGH IMPEDANCE

Notes

15.If WE is Low when CE goes Low, the outputs remain in the High Impedance State.

16.CE or WE are greater than VIH during address transitions.

Document Number: 001-06431 Rev. *H

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Contents Functional Description FeaturesLogic Block Diagram Cypress Semiconductor Corporation 198 Champion CourtPin Configurations Pin DefinitionsDevice Operation AutoStore 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 Alarm Watchdog TimerCalibrating 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 CycleRTC Characteristics Inputs and Outputs Mode PowerTruth 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 tableSales, Solutions, and Legal Information Worldwide Sales and Design Support Products PSoC SolutionsUSB