Silan

Semiconductors

SC9012

HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD

Rev: 2.1

2002-02-28

5

The waveforms of leader code, bit “0” and bit “1” refer to follow diagram:

4.5ms

4.5ms

Tm

Tm

Tm=0.56ms

Tm

3Tm

Leader

Code

Bit“0”

Bit“1”

6. DOUBLE KEY OPERATION

There are 6 double keys operation, such as K21 connected with K22 ~ K24; K25 connected with K26 ~ K28, refer to

the follow table:

The Primary Key

The Secondary Key

D0

D1

D2

D3

D4

D5

D6

D7

K22

1

0

1

01100

K23

0

1

1

01100

K21

K24

1

1

1

01100

K26

1

0

0

11100

K27

0

1

0

11100

K25

K28

1

1

0

11100

When any of the double or multiple key combinations are pressed, except the 6 keys mentioned above, there is no

output.

In addition, Double Key Operation is useful for tape deck recording operation. Press the K21 or K23 key at the first

then followed by the secondary key such as K22~K24; K26~K28.

Please refer to the follow diagram:

1. Double Key Operation available

T>126ms