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Aduc812 – Analog Devices ADuC812 User Manual

Page 48

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REV. B

ADuC812

–48–

12 MHz

Variable Clock

Parameter

Min

Max

Min

Max

Unit

Figure

EXTERNAL DATA MEMORY READ CYCLE

t

RLRH

RD Pulsewidth

400

6t

CK

– 100

ns

53

t

AVLL

Address Valid after ALE Low

43

t

CK

– 40

ns

53

t

LLAX

Address Hold after ALE Low

48

t

CK

– 35

ns

53

t

RLDV

RD Low to Valid Data In

252

5t

CK

– 165

ns

53

t

RHDX

Data and Address Hold after

RD

0

0

ns

53

t

RHDZ

Data Float after

RD

97

2t

CK

–70

ns

53

t

LLDV

ALE Low to Valid Data In

517

8t

CK

– 150

ns

53

t

AVDV

Address to Valid Data In

585

9t

CK

– 165

ns

53

t

LLWL

ALE Low to

RD or WR Low

200

300

3t

CK

– 50

3t

CK

+ 50

ns

53

t

AVWL

Address Valid to

RD or WR Low

203

4t

CK

– 130

ns

53

t

RLAZ

RD Low to Address Float

0

0

ns

53

t

WHLH

RD or WR High to ALE High

43

123

t

CK

– 40

6t

CK

– 100

ns

53

MCLK

ALE (O)

PSEN (O)

RD (O)

PORT 0 (I/O)

PORT 2 (O)

t

WHLH

t

LLDV

t

LLWL

t

RLRH

t

AVWL

t

LLAX

t

AVLL

t

RLAZ

t

RHDX

t

RHDZ

t

AVDV

A0–A7 (OUT)

DATA (IN)

A16–A23

A8–A15

t

RLDV

Figure 52. External Data Memory Read Cycle