Preliminary

2GB Unbuffered DIMM

Rev. 0.0 April 2004

DDR SDRAM

Parameter

Symbol

B3

(DDR333@CL=2.5))

A2

(DDR266@CL=2.0)

B0

(DDR266@CL=2.5))

Unit

Note

Min

Max

Min

Max

Min

Max

Mode register set cycle time

tMRD

12

15

15

ns

DQ & DM setup time to DQS

tDS

0.45

0.5

0.5

ns

j, k

DQ & DM hold time to DQS

tDH

0.45

0.5

0.5

ns

j, k

Control & Address input pulse width

tIPW

2.2

2.2

2.2

ns

8

DQ & DM input pulse width

tDIPW

1.75

1.75

1.75

ns

8

Power down exit time

tPDEX

6

7.5

7.5

ns

Exit self refresh to non-Read command

tXSNR

75

75

75

ns

Exit self refresh to read command

tXSRD

200

200

200

tCK

Refresh interval time

tREFI

7.8

7.8

7.8

us

4

Output DQS valid window

tQH

tHP

-tQHS

-

tHP

-tQHS

-

tHP

-tQHS

-ns

11

Clock half period

tHP

tCLmin

or tCHmin

-

tCLmin

or tCHmin

-

tCLmin

or tCHmin

-

ns

10, 11

Data hold skew factor

tQHS

0.55

0.75

0.75

ns

11

DQS write postamble time

tWPST

0.4

0.6

0.4

0.6

0.4

0.6

tCK

2

Active to Read with Auto precharge

command

tRAP

18

20

20

Autoprecharge write recovery +

Precharge time

tDAL

(tWR/tCK)

+(tRP/tCK)

(tWR/tCK)

+(tRP/tCK)

(tWR/tCK)

+(tRP/tCK)

tCK

13

System Characteristics for DDR SDRAM

The following specification parameters are required in systems using DDR333 & DDR266 devices to ensure proper sys-

tem performance. these characteristics are for system simulation purposes and are guaranteed by design.

Table 1 : Input Slew Rate for DQ, DQS, and DM

Table 2 : Input Setup & Hold Time Derating for Slew Rate

Table 3 : Input/Output Setup & Hold Time Derating for Slew Rate

AC CHARACTERISTICS

DDR333

DDR266

PARAMETER

SYMBOL

MIN

MAX

MIN

MAX

Units

Notes

DQ/DM/DQS input slew rate measured between

VIH(DC), VIL(DC) and VIL(DC), VIH(DC)

DCSLEW

TBD

TBD

TBD

TBD

V/ns

a, m

Input Slew Rate

tIS

tIH

Units

Notes

0.5 V/ns

0

0

ps

i

0.4 V/ns

+50

0

ps

i

0.3 V/ns

+100

0

ps

i

Input Slew Rate

tDS

tDH

Units

Notes

0.5 V/ns

0

0

ps

k

0.4 V/ns

+75

+75

ps

k

0.3 V/ns

+150

+150

ps

k