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Analog Devices ADSP-21020 User Manual

Page 20

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ADSP-21020

REV. C

–20–

Memory Write

K/B/T Grade

K/B/T Grade

B/T Grade

K Grade

20 MHz

25 MHz

30 MHz

33.3 MHz Frequency Dependency*

Parameter

Min

Max

Min

Max

Min Max

Min Max Min

Max

Unit

Timing Requirement:

12

t

DAAK

xACK Delay from Address, Select

27

18

6

9

27 + 7DT/8

ns

t

DWAK

xACK Delay from xWR Low

15

10

10

5

15 + DT/2

ns

t

SAK

xACK Setup before CLKIN High

14

12

0

9

14 + DT/4

ns

t

HAK

xACK Hold after CLKIN High

0

0

0

ns

Switching Characteristic:
t

DAWH

Address, Select to xWR Deasserted

37

28

21

18

37+ 15DT/16

ns

t

DAWL

Address, Select to xWR Low

11

7

5

3

11 + 3DT/8

ns

t

WW

xWR

Pulse Width

26

20

16

15

26 + 9DT/16

ns

t

DDWH

Data Setup before xWR High

23

18

14

13

23 + DT/2

ns

t

DWHA

Address, Select Hold after xWR
Deasserted

1

0

0

0

1 + DT/16

ns

t

HDWH

Data Hold after xWR Deasserted

1

0

–1

–1

–1

DT/16

ns

t

DAP

xPAGE Delay from Address, Select

1

1

1

1

ns

t

DCKWL

CLKIN High to xWR Low

16

26

13

24

12

22

11

21

16 + DT/4 26 + DT/4

ns

t

WWR

xWR

High to xWR or xRD Low

17

13

10

8

17 + 7DT/16

ns

t

DDWR

Data Disable before xWR or xRD
Low

13

9

7

5

13 + 3DT/8

ns

t

WDE

xWR

Low to Data Enabled

0

–1

–1

–1

DT/16

ns

NOTES
*DT = t

C

– 50 ns

See “System Hold Time Calculation” in “Test Conditions” section for calculating hold times given capacitive and DC loads.
x = PM or DM; Address = PMA23-0, DMA31-0; Data = PMD47-0, DMD39-0; Select = PMS1-0, DMS3-0.