Cypress CY62256 manual Switching Characteristics Over the Operating Range6, Switching Waveforms

CY62256

Switching Characteristics Over the Operating Range[6]

			CY62256− 55		CY62256− 70
Parameter		Description	Min.	Max.	Min.	Max.	Unit
Read Cycle
tRC	Read Cycle Time		55		70		ns
tAA	Address to Data Valid			55		70	ns
tOHA	Data Hold from Address Change		5		5		ns
tACE		LOW to Data Valid		55		70	ns
	CE
tDOE		LOW to Data Valid		25		35	ns
	OE
tLZOE		LOW to Low-Z[7]	5		5		ns
	OE
tHZOE		HIGH to High-Z[7, 8]		20		25	ns
	OE
tLZCE		LOW to Low-Z[7]	5		5		ns
	CE
tHZCE		HIGH to High-Z[7, 8]		20		25	ns
	CE
tPU		LOW to Power-up	0		0		ns
	CE
tPD		HIGH to Power-down		55		70	ns
	CE
Write Cycle[9, 10]
tWC	Write Cycle Time		55		70		ns
tSCE		LOW to Write End	45		60		ns
	CE
tAW	Address Set-up to Write End		45		60		ns
tHA	Address Hold from Write End		0		0		ns
tSA	Address Set-up to Write Start		0		0		ns
tPWE		Pulse Width	40		50		ns
	WE
tSD	Data Set-up to Write End		25		30		ns
tHD	Data Hold from Write End		0		0		ns
tHZWE		LOW to High-Z[7, 8]		20		25	ns
	WE
tLZWE		HIGH to Low-Z[7]	5		5		ns
	WE

Switching Waveforms

Read Cycle No. 1[11, 12]

tRC

ADDRESS

tAA

tOHA

DATA OUT PREVIOUS DATA VALID

Notes:

DATA VALID

6.Test conditions assume signal transition time of 5 ns or less, timing reference levels of 1.5V, input pulse levels of 0 to 3.0V, and output loading of the specified IOL/IOH and 100-pF load capacitance.

7.At any given temperature and voltage condition, tHZCE is less than tLZCE, tHZOE is less than tLZOE, and tHZWE is less than tLZWE for any given device.

8.tHZOE, tHZCE, and tHZWE are specified with CL = 5 pF as in (b) of AC Test Loads. Transition is measured ± 500 mV from steady-state voltage.

9.The internal Write time of the memory is defined by the overlap of CE LOW and WE LOW. Both signals must be LOW to initiate a Write and either signal can terminate a Write by going HIGH. The data input set-up and hold timing should be referenced to the rising edge of the signal that terminates the Write.

10.The minimum Write cycle time for Write cycle #3 (WE controlled, OE LOW) is the sum of tHZWE and tSD

11.Device is continuously selected. OE, CE = VIL.

12.WE is HIGH for Read cycle.

Document #: 38-05248 Rev. *B Page 4 of 11