Silan

Semiconductors

SC3010

HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD

Rev: 2.1

2002-02-28

5

Start Bits (2xLogic 1), 1 Control Bit, 5 System Bits, and 6 Command Bits. Please refer to the diagram above for the

data output format. (See also Command and System Matrixes).

After a legal key operation is performed, the KO outputs are switched off and a 16-bit debounce time period is

experienced followed by a 2-bit scan cycle time. During the scanning cycle the outputs are switched to the

conductive state one at a time.

Code is transmitted using a biphase technique. Please refer to the diagram below. The MDOUT Output Signal

transmits the generated data modulated by 1/12 of the oscillator frequency with a 25% duty factor.

Logic 1

Logic 0

where: 1 bit-time=3x2

Figure 2: Biphase Code Transmission Technique

Outputs (KO0~KO7) are open drain n-channel and conduct when the circuit is in the quiescent state.

4. SYSTEM MODES

a). Combined System Mode (SMS=Low)

The KI and the C Sense Inputs have p-channel pull-up transistors (meaning they are normally in HIGH state).

They are pulled to LOW state when an output is connected, to them as a result of a legal key operation. A legal key

operation in the KI-KO or C-KO Matrix will initiate a debounce cycle. Once key contact has been established for 18-

bit time without any interruption, the Oscillator Enable Signal is latched and the key may be released. The device is

reset when there is an interruption during the 18-bit time period. At the end of the debounce cycle, KO Outputs are

switched off and two scan cycles begins.

When KI or C Input senses a low level output, a Latch-Enable Signal is fed to the System (C-Input) or Command

(KI-Input) Latches. After latching a system number, the device will generate the last command (i.e. all command bits

logic 1) in the selected system for as long as the key is pressed. Latching of a command number causes the chip to

generate this command together with the system number stored in the system latch. By releasing the key, the device

will be reset if no data is to be transmitted at the time. The complete code frame is transmitted even if the key is

released during code transmission.