K4T56043QF Datasheet, PDF (18/27 Pages) Samsung semiconductor – 256Mb F-die DDR2 SDRAM

256Mb F-die DDR2 SDRAM
DDR2 SDRAM
Parameter
Symbol
Mode register set
command cycle time
tMRD
Write postamble
tWPST
Write preamble
tWPRE
Address and control
input hold time
tIH(base)
Address and control
input setup time
tIS(base)
Read preamble
tRPRE
Read postamble
tRPST
Active to active
command period for
1KB page size
products
tRRD
Active to active
command period for
2KB page size
products
Four Activate Window
for 1KB page size
products
Four Activate Window
for 2KB page size
products
tRRD
tFAW
tFAW
CAS to CAS command tCCD
delay
Write recovery time
tWR
Auto precharge write
recovery + precharge
time
tDAL
Internal write to read
command delay
tWTR
Internal read to
precharge command
delay
tRTP
Exit self refresh to a
non-read command
tXSNR
Exit self refresh to a
read command
tXSRD
Exit precharge power tXP
down to any non-read
command
Exit active power down tXARD
to read command
DDR2-667
min
max
2
x
0.4
0.6
0.35
x
275
x
200
x
0.9
1.1
0.4
0.6
7.5
x
10
x
37.5
50
2
15
x
WR+tR
x
P
7.5
x
7.5
tRFC +
10
200
2
x
2
x
DDR2-533
min max
2
x
0.4
0.6
0.35
x
375
x
250
x
0.9
1.1
0.4
0.6
7.5
x
10
x
37.5
50
2
15
x
WR+tR
x
P
7.5
x
7.5
tRFC +
10
200
2
x
2
x
DDR2-400
min
max
2
x
0.4
0.6
0.35
x
475
x
350
x
0.9
1.1
0.4
0.6
7.5
x
10
x
37.5
50
2
15
x
WR+tR
x
P
10
x
7.5
tRFC +
10
200
2
x
2
x
Units Notes
tCK
tCK
19
tCK
ps
14,16,
18,23
ps
14,16,
18,22
tCK
28
tCK
28
ns
12
ns
12
ns
ns
tCK
ns
tCK
23
ns
33
ns
11
ns
tCK
tCK
tCK
9
Page 18 of 27
Rev. 1.5 Feb. 2005