Silan

Semiconductors

SC7461

HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD

Rev: 2.2

2002-02-28.

5

There is no order of priority given in key input. This means that keys designated for the double keying operation

may be pressed in any sequence. When two keys (designated for the double key operation) are pressed

simultaneously, a series of pulse is outputted according to each key input. Pressing other keys that are NOT

intended for the double key operation do NOT generate any output.

The Key Matrix is given in the following diagram.

5

1

13

9

21

17

29

25

6

2

14

10

22

18

30

26

7

3

15

11

23

19

31

27

8

4

16

12

24

20

0

28

KI0

KI1

KI2

KI3

KO0 KO1 KO2 KO3 KO4 KO5 KO6 KO7

FIGURE 2. KEY MATRIX

3.DOUBLE KEY OPERATION

Double Key Operation is useful for tape deck recording operation. The following table shows the Key Data

corresponding to the double keys pressed. Also refer to the Key Input Section.

Key

D0

D1

D2

D3

D4

D5

D6

D7

K20+K21

1

010

110

0

K20+K22

0

110

110

0

K20+K23

1

110

110

0

NOTE: Key Data--D6 and D7 may be preset to "0", "1" by mask option.

Key 20

Key 21

Key 22

Key 20

Transmission

Data

Key 20&21

Transmission

Data

Key 21

Transmission

Data

Transmission

Stops

Key 22

Transmission

Data

Key 20&22

Transmission

Data

(H=Key-ON)

FIGURE 3. TRANSMISSION DATA DIAGRAM