K4D551638D Datasheet, PDF (14/18 Pages) Samsung semiconductor – 256Mbit GDDR SDRAM

K4D551638D-TC
AC CHARACTERISTICS
Parameter
CK cycle time
CL=3
CL=4
CK high level width
CK low level width
DQS out access time from CK
Output access time from CK
Data strobe edge to Dout edge
Read preamble
Read postamble
CK to valid DQS-in
DQS-In setup time
DQS-in hold time
DQS write postamble
DQS-In high level width
DQS-In low level width
Address and Control input setup
Address and Control input hold
DQ and DM setup time to DQS
DQ and DM hold time to DQS
Clock half period
Data output hold time from DQS
Symbol
tCK
tCH
tCL
tDQSCK
tAC
tDQSQ
tRPRE
tRPST
tDQSS
tWPRES
tWPREH
tWPST
tDQSH
tDQSL
tIS
tIH
tDS
tDH
tHP
tQH
-50
Min
Max
5.0
10
-
0.45
0.55
0.45
0.55
-0.55
0.55
-0.65
0.65
-
0.4
0.9
1.1
0.4
0.6
0.72
1.28
0
-
0.25
-
0.4
0.6
0.35
-
0.35
-
0.6
-
0.6
-
0.4
-
0.4
-
tCLmin
or
-
tCHmin
tHP- 0.5
-
256M GDDR SDRAM
-60
Min
Max
6.0
12
-
0.45
0.55
0.45
0.55
-0.6
0.6
-0.7
0.7
-
0.45
0.9
1.1
0.4
0.6
0.75
1.25
0
-
0.25
-
0.4
0.6
0.35
-
0.35
-
0.8
-
0.8
-
0.45
-
0.45
-
tCLmin
or
-
tCHmin
tHP-0.55
-
Unit Note
ns
ns
tCK
tCK
ns
ns
ns
1
tCK
tCK
tCK
ns
tCK
tCK
tCK
tCK
ns
ns
ns
ns
ns
1
ns
1
AC CHARACTERISTICS (I)
Parameter
Symbol
Row cycle time
Refresh row cycle time
Row active time
RAS to CAS delay for Read
RAS to CAS delay for Write
Row precharge time
Row active to Row active
Last data in to Row precharge @Nor-
mal Precharge
Last data in to Row precharge @Auto
Precharge
Last data in to Read command
Col. address to Col. address
Mode register set cycle time
Auto precharge write recovery + Pre-
charge
Exit self refresh to read command
Power down exit time
Refresh interval time
tRC
tRFC
tRAS
tRCDRD
tRCDWR
tRP
tRRD
tWR
tWR_A
tCDLR
tCCD
tMRD
tDAL
tXSR
tPDEX
tREF
-50
Min
12
14
8
4
2
4
2
3
3
2
1
2
7
200
1tCK+tIS
7.8
Max
-
-
100K
-
-
-
-
-
-
-
-
-
-
-
-
-
-60
Min
10
12
7
3
2
3
2
3
3
1
1
2
6
200
1tCK+tIS
7.8
Max
-
-
100K
-
-
-
-
-
-
-
-
-
-
-
-
-
Note : 1. For normal write operation, even numbers of Din are to be written inside DRAM
Unit Note
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
1
tCK
1
tCK
1
tCK
tCK
tCK
tCK
ns
us
- 14 -
Rev 1.8 (Oct. 2003)