Silan

Semiconductors

SC6121

HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD

Rev: 1.2

2002-02-28

4

FUNCTIONAL DESCRIPTION

1. TRANSMISSION CODE

The transmission code consists of a leader code, 16-bits custom codes, and 8-bits data codes. The inverse

code of the data code is also sent simultaneously. The following diagram shows this one frame construction.

C0 C1 C2 C3

C5

C4

C6 C7

D0 D1 D2 D3 D4

D0 D1 D2 D3 D4 D5 D6 D7

C0'

C0

C0'

C1

C0'

C2

C0'

C3

C0'

C4

C0'

C5

C0'

C6

C0'

C7

D5 D6 D7

Leader

Code

Custom Code

8bits

Custom Code'

8bits

Key Data

8bits

Key Data

8bits

The leader codes consist of a 9ms carrier waveform followed by a 4.5ms OFF waveform. It is used as the leader

for the following code. Thus, when reception is configured by a microcomputer, the time relationship between the

reception detection and other processes can be managed efficiently. The code uses the PPM (Pulse Position

Modulation) Method, with "0" and "1" differentiated by the time between pulses. Each code consists of 8 bits, and

simultaneous transmission of the inverse code allows configuration of a system with an extremely low error rate.

2. KEY INPUT MATRIX

The Key Input Matrix of SC6121 if given below:

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

32

28

KI0

KI1

KI2

KI3

3. KEY INPUT

A total of 32 keys can be connected by SC6121 Key Input Pins--KI0~KI3 and the Timing Signal Output Pins

KI/O0~KI/O7.

Double Key Operation is possible for only Key No.21 in combination with other keys connected to the KI/O5 line

namely: Key No.22,23 or 24.thus, only the following key combinations may be used for the double key operation:

1. Key Nos.21 and 22

2. Key Nos.21 and 23

3. Key Nos.21 and 24