SMART Modular 512MB DDR2 SDRAM SM646UDR26485-2-I Manuale Utente
Codici prodotto
SM646UDR26485-2-I
SM646UDR26485-2-I
January 31, 2006
Corporate Headquarters: P. O. Box 1757, Fremont, CA 94538, USA • Tel:(510) 623-1231 • Fax:(510) 623-1434 • E-mail: info@smartm.com
Europe: 5 Kelvin Park South, Kelvin South, East Kilbride, G75 ORH, United Kingdom • Tel: +44-870-870-8747 • Fax: +44-870-870-8757
Asia/Pacific: Plot 18, Lrg Jelawat 4, Kawasan Perindustrian Seberang Jaya 13700, Prai, Penang, Malaysia • Tel: +604-3992909 • Fax: +604-3992903
Europe: 5 Kelvin Park South, Kelvin South, East Kilbride, G75 ORH, United Kingdom • Tel: +44-870-870-8747 • Fax: +44-870-870-8757
Asia/Pacific: Plot 18, Lrg Jelawat 4, Kawasan Perindustrian Seberang Jaya 13700, Prai, Penang, Malaysia • Tel: +604-3992909 • Fax: +604-3992903
23
Parameter
Symbol
3.0ns @ CL5.0
DDR2-667
Unit
Notes
Min
Max
CKE low to CK,CK# uncertainity
t
DELAY
3.475
3.475
ns
24
ACTIVE to ACTIVE (same bank) command
t
RC
60
-
ns
ACTIVE bank a to ACTIVE bank b command
t
RRD
7.5
-
ns
23
ACTIVE to READ or WRITE delay
t
RCD
15
-
ns
ACTIVE to PRECHARGE command
t
RAS
45
70000
ns
16
Internal READ to precharge command delay
t
RTP
7.5
-
ns
19, 23
Write recovery time
t
WR
15
-
ns
23
Auto precharge write recovery + Precharge time
t
DAL
t
WR
+ t
RP
-
t
CK
18
Internal WRITE to READ command delay
t
WTR
7.5
-
ns
23
PRECHARGE command period
t
RP
15
-
ns
LOAD MODE command cycle time
t
MRD
2
-
t
CK
REFRESH to REFRESH command interval
t
RFC
105
-
ns
10
Average periodic refresh Interval
t
REFI
-
7.8
µs
10
Exit self refresh to non-READ command
t
XSNR
t
RFC
(min)
+ 10
-
ns
Exit self refresh to READ command
t
XSRD
200
-
t
CK
ODT turn-on delay
t
AOND
2
2
t
CK
ODT turn-on
t
AON
t
AC
(min)
t
AC
(max)
+ 1000
ps
21
ODT turn-off delay
t
AOFD
2.5
2.5
t
CK
ODT turn-off
t
AOF
t
AC
(min)
t
AC
(max)
+ 600
ps
22
ODT turn-on (power-down mode)
t
AONPD
t
AC
(min) +
2000
2*t
CK
+
t
AC
(max)
+ 1000
ps
ODT turn-off (power-down mode)
t
AOFPD
t
AC
(min) +
2000
2.5*t
CK
+
t
AC
(max)
+ 1000
ps
ODT to power-down entry latency
t
ANPD
3
t
CK
ODT power-down exit latency
t
AXPD
8
t
CK
Exit active power-down to READ command, MR[bit12=0]
t
XARD
2
-
t
CK
Exit active power-down to READ command, MR[bit12=1]
t
XARDS
7 - AL
-
t
CK
Exit precharge power down to any non-read command
t
XP
2
-
t
CK
CKE minimum pulse width (high and low pulse width)
t
CKE
3
-
t
CK
Device AC Operating Conditions (Contd.)