Rev. 0.8 / Oct. 2007

27

Specific Notes for dedicated AC parameters

1. User can choose which active power down exit timing to use via MRS(bit 12). tXARD is expected to be used for fast

active power down exit timing. tXARDS is expected to be used for slow active power down exit timing where a lower

power value is defined by each vendor data sheet.

2. AL = Additive Latency

3. This is a minimum requirement. Minimum read to precharge timing is AL + BL/2 providing the tRTP and tRAS(min)

have been satisfied.

4. A minimum of two clocks (2 * tCK) is required irrespective of operating frequency

5. Timings are guaranteed with command/address input slew rate of 1.0 V/ns. See System Derating for other slew rate

values.

6. Timings are guaranteed with data, mask, and (DQS/RDQS in singled ended mode) input slew rate of 1.0 V/ns.

See System Derating for other slew rate values.

7. Timings are guaranteed with CK/CK differential slew rate of 2.0 V/ns. Timings are guaranteed for DQS signals with a

differen tial slew rate of 2.0 V/ns in differential strobe mode and a slew rate of 1V/ns in single ended mode. See System

Derating for other slew rate values.

8. tDS and tDH derating table (for DDR2- 400 / 533)

1) For all input signals the total tDS(setup time) and tDH(hold time) required is calculated by adding the datasheet value

to the derating value listed in above Table.

Setup(tDS) nominal slew rate for a rising signal is defined as the slew rate between the last crossing of VREF(dc) and the

first crossing of Vih(ac)min. Setup(tDS) nominal slew rate for a falling signal is defined as the slew rate between the last

crossing of VREF(dc) and the first crossing of Vil(ac)max. If the actual signal is always earlier than the nominal slew rate

line between shaded ‘ VREF(dc) to ac region’, use nominal slew rate for derating value(see Fig a.) If the actual signal is

later than the nominal slew rate line anywhere between shaded ‘VREF(dc) to ac region’, the slew rate of a tangent line to

the actual signal from the ac level to dc level is used for derating value(see Fig b.)

Hold(tDH) nominal slew rate for a rising signal is defined as the slew rate rate between the last crossing of Vil(dc) max and

the first crossing of VREF(dc). Hold (tDH) nominal slew rate for a falling signal is defined as the slew rate between the last

crossing of Vih(dc) min and the first crossing of VREF(dc). If the actual signal is earlier than the nominal slew rate line

anywhere between shaded ‘dc to VREF(dc) region’, the slew rate of a tangent line to the actual signal from the dc level to

VREF(dc) level is used for derating value(see Fig d.)

△ tD

S

△ tD

H

△ tD

S

△ tD

H

△ tD

S

△ tD

H

△ tD

S

△ tD

H

△ tD

S

△ tD

H

△ tD

S

△ tD

H

△ tD

S

△ tD

H

△ tD

S

△ tD

H

△ tD

S

△ tD

H

2.0

125

45

125

45

+125 +45

-

-

-

-

-

-

-

-

-

-

-

-

1.5

83

21

83

21

+83

+21

95

33

--

--

--

--

--

1.0

0

0

0

0

0

0

12

12

24

24

--

--

--

--

0.9

-

-

-11

-14

-11

-14

1

-2

13102522

-

-

-

-

-

-

0.8

-

-

-

-

-25

-31

-13

-19

-1

-7

11

5

23

17

-

-

-

-

0.7

--

--

--

-31

-42

-42

-19

-7

-8

5

-6

17

6

--

0.6

--

--

--

--

-43

-59

-31

-47

-19

-35

-7

-23

5

-11

0.5

--

--

--

--

--

-74

-89

-62

-77

-50

-65

-38

-53

0.4

-

-

-

-

-

-

-

-

-

-

-

-

-127 -140 -115 -128 -103 -116

tDS, tDH Derating Values(ALL units in 'ps', Note 1 applies to entire Table)

1.6 V/ns

1.4 V/ns

1.2 V/ns

1.0 V/ns

4.0 V/ns

3.0 V/ns

0.8 V/ns

DQ

Slew

rate

V/ns

DQS, DQS Differential Slew Rate

2.0 V/ns

1.8 V/ns