CY62256
Switching Characteristics Over the Operating Range[7]
CY62256−55
CY62256−70
Parameter
Description
Min.
Max.
Min.
Max.
Unit
Read Cycle
tRC
tAA
tOHA
tACE
tDOE
tLZOE
tHZOE
tLZCE
Read Cycle Time
55
5
70
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Address to Data Valid
Data Hold from Address Change
CE LOW to Data Valid
OE LOW to Data Valid
OE LOW to Low-Z[8]
55
70
5
55
25
70
35
5
5
0
5
5
0
OE HIGH to High-Z[8, 9]
CE LOW to Low-Z[8]
20
20
55
25
25
70
tHZCE
tPU
tPD
CE HIGH to High-Z[8, 9]
CE LOW to Power-up
CE HIGH to Power-down
Write Cycle[10, 11]
tWC
tSCE
tAW
tHA
tSA
tPWE
tSD
tHD
tHZWE
tLZWE
Write Cycle Time
55
45
45
0
70
60
60
0
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
CE LOW to Write End
Address Set-up to Write End
Address Hold from Write End
Address Set-up to Write Start
WE Pulse Width
Data Set-up to Write End
Data Hold from Write End
WE LOW to High-Z[8, 9]
WE HIGH to Low-Z[8]
0
0
40
25
0
50
30
0
20
25
5
5
Switching Waveforms
Read Cycle No. 1[12, 13]
t
RC
ADDRESS
t
AA
t
OHA
DATA OUT
PREVIOUS DATA VALID
DATA VALID
Notes:
7. 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
/I and 100-pF load capacitance.
I
OL OH
8. At any given temperature and voltage condition, t
is less than t
, t
is less than t
, and t
is less than t
for any given device.
HZCE
LZCE HZOE
LZOE
HZWE
LZWE
9.
t
, t
, and t
are specified with C = 5 pF as in (b) of AC Test Loads. Transition is measured ±500 mV from steady-state voltage.
HZOE HZCE
HZWE L
10. The internal Write time of the memory is defined by the overlap of CELOW 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.
11. The minimum Write cycle time for Write cycle #3 (WE controlled, OE LOW) is the sum of t
and t
SD
HZWE
12. Device is continuously selected. OE, CE = V .
IL
13. WE is HIGH for Read cycle.
Document #: 38-05248 Rev. *C
Page 5 of 12
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