MT89L85

Advance Information

2

Figure 2 - Pin Connections

Pin Description

Pin #

Name

Description

44

PLCC

48

SSOP

22

DTA

Data Acknowledgment (Open Drain Output). This active low output indicates that a

data bus transfer is complete. A pull-up resistor is required at this output.

3-5

7-11

3-5

7-11

STi0-

STi7

ST-BUS Input 0 to 7 (Inputs). Serial data input streams. These streams have 32

channels at data rates of 2.048 Mbit/s.

12

12,36

+3.3 Volt Power Supply.

13

RESET Device Reset (5v-tolerant input). This pin is only available for the 48-pin SSOP

package. This active low input puts the MT89L85 in its reset state. It clears the internal

counters anf registers. All ST-BUS outputs are set to the high impedance state. This

RESET pin must be held low for a minimum of 100nsec to reset the device.

13

14

F0i

Frame Pulse (Input). This input accepts and automatically identifies frame

synchronization signals formatted according to different backplane specifications such

as ST-BUS and GCI.

14

15

C4i

Clock (Input). 4.096 MHz serial clock for shifting data in and out of the data streams.

15-17

19-21

16-18

20-22

A0-A5 Address 0 to 5 (Inputs). These lines provide the address to MT89L85 internal

registers.

22

23

DS

Data Strobe (Input). This is the input for the active high data strobe on the

microprocessor interface. This input operates with CS to enable the internal read and

write generation.

(JEDEC MO-118, 300mil Wide)

7

8

9

10

11

12

13

14

15

16

39

38

37

36

35

34

33

32

31

30

17

29

STi3

STi4

STi5

STi6

STi7

F0i

C4i

A0

A1

A2

STo3

STo4

STo5

STo6

STo7

D0

D1

D2

D3

D4

44 PIN PLCC

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

1

48 PIN SSOP

47

46

45

44

43

42

41

40

39

38

37

36

35

34

33

32

31

30

29

28

ODE

STo0

STo1

STo2

NC

STo3

STo4

STo5

STo6

STo7

D0

D1

D2

D3

D4

NC

D5

D6

DTA

STi0

STi1

STi2

NC

STi3

STi4

STi5

STi6

STi7

RESET

F0i

C4i

A0

A1

A2

NC

A3

A4

48

CSTo

21

27

D7

A5

22

26

CS

DS

23

25

R/W

24