Page 4

V.2.0 Mar 8,2002

C. Transmission Timing

* t1: Key pressing > 32ms

* t2: Transmission time t3 + 108ms ( Four frame )

If t1 is over t3 + 108ms, DOUT will be transmitted again.

[ ( Pressing time ) MOD ( t3 + 108ms ) + 1 ] * 108ms + t3

* t3: Oscillator stable time.

OSC * 384 = 0.8ms

* t4: 3-Bits( Head ) + 2-Bits( Custom Code ) + 7-Bits( Data ) + 6-Bits( Empty ) = 18-Bits (27ms)

* OSC: 455KHz resonator

Key In

t1

OSC

LED

t2

DOUT

t3

t4

Frame 1

Frame 2

Frame 3

Frame 4

SM5021

三合微科股份有限公司

ENCODER