W3EG2256M72ASSR-JD3 Datasheet, PDF (8/14 Pages) White Electronic Designs Corporation – 4GB - 2x256Mx72 DDR SDRAM REGISTERED ECC, w/PLL

White Electronic Designs
W3EG2256M72ASSR-JD3
-AJD3
PRELIMINARY
DDR SDRAM COMPONENT ELECTRICAL CHARACTERISTICS AND
RECOMMENDED AC OPERATING CONDITIONS
AC Characteristics
262
263/265
202
Parameter
Symbol
Access window of DQs from CK, CK#
tAC
CK high-level width
tCH
CK low-level width
tCL
Clock cycle time
CL=2.5 tCK (2.5)
CL=2 tCK (2)
DQ and DM input hold time relative to DQS
tDH
DQ and DM input setup time relative to DQS
tDS
DQ and DM input pulse width (for each input)
tDIPW
Access window of DQS from CK, CK#
tDQSCK
DQS input high pulse width
tDQSH
DQS input low pulse width
tDQSL
DQS-DQ skew, DQS to last DQ valid, per group, per access tDQSQ
Write command to first DQS latching transition
tDQSS
DQS falling edge to CK rising - setup time
tDSS
DQS falling edge from CK rising - hold time
tDSH
Half clock period
tHP
Data-out high-impedance window from CK, CK#
tHZ
Data-out low-impedance window from CK, CK#
tLZ
Address and control input hold time (fast slew rate)
tIHf
Address and control input set-up time (fast slew rate)
tISf
Address and control input hold time (slow slew rate)
tIHs
Address and control input setup time (slow slew rate)
tISs
Address and control input pulse width (for each input)
tIPW
LOAD MODE REGISTER command cycle time
tMRD
DQ-DQS hold, DQS to first DQ to go non-valid, per access
tQH
Data hold skew factor
tQHS
ACTIVE to PRECHARGE command
tRAS
ACTIVE to READ with Auto precharge command
tRAP
ACTIVE to ACTIVE/AUTO REFRESH command period
tRC
AUTO REFRESH command period
tRFC
Min Max
-0.7 +0.7
0.45 0.55
0.45 0.55
6
13
7.5
13
0.45
0.45
1.75
-0.6 +0.60
0.35
0.35
0.5
0.75 1.25
0.2
0.2
tCH, tCL
+0.70
-0.70
0.75
0.75
0.80
0.80
2.2
15
tHP-tQHS
0.75
45 120,000
15
60
120
Min Max
-0.75 +0.75
0.45 0.55
0.45 0.55
7.5
13
7.5/10 13
0.5
0.5
1.75
-0.75 +0.75
0.35
0.35
0.5
0.75 1.25
0.2
0.2
tCH, tCL
+0.75
-0.75
0.90
0.90
1
1
2.2
15
tHP-tQHS
0.75
45 120,000
20
65
120
Min Max
-0.8 +0.8
0.45 0.55
0.45 0.55
8
13
10
13
0.6
0.6
2
-0.8 +0.8
0.35
0.35
0.5
0.75 1.25
0.2
0.2
tCH, tCL
+0.8
-0.8
1.1
1.1
1.1
1.1
2.2
16
tHP-tQHS
1
45 120,000
20
70
120
Units
ns
tCK
tCK
ns
ns
ns
ns
ns
ns
tCK
tCK
ns
tCK
tCK
tCK
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Notes
16
16
22
22
14,17
14,17
17
13,14
18
8,19
8,20
6
6
6
6
13,14
15
21
November, 04
Rev. 3
8
White Electronic Designs Corporation • [phone] • www.wedc.com