Tel: 886-2-66296288

Fax: 886-2-29174598

URL: http://www.princeton.com.tw

PT2260 V1.4

- 5 -

April, 2006

Remote Control Encoder

PT2260

FUNCTION DESCRIPTION

PT2260 encodes the code address and data set at A0 ~ A7, A8/D3, A9/D2, D1 and D0 into a special

waveform and outputs it to the DOUT when any of the data pins is tied to high. This waveform is fed to

the RF modulator for transmission. The transmitted radio frequency is received by the RF demodulator

and reshaped into the special waveform. PT2270 (or PT2272) is then used to decode the waveform

and set the corresponding output pin(s). Thus completing a remote control encoding and decoding

function.

RF OPERATION

CODE BITS

A Code Bit is the basic component of the encoded waveform, and can be classified as either an AD

(Address/Data) Bit or a SYNC (Synchronous) Bit.

Address/Data (AD) Bit Waveform

An AD Bit can be designated as Bit “0”, “1”, or “f” if it is in low, high or floating state respectively. One bit

waveform consists of 2 pulse cycles. Each pulse cycle has 512 oscillating clock periods. For further

details, please refer to the diagram below:

α

1 bit = 10 24

α

12 8

α

12 8

α

38 4

α

OSC

Bit"0 "

Bit"1 "

Bit"f"

Flo a ting

where:

α=Oscillating Clock Period

Synchronous (Sync.) Bit Waveform

The Synchronous Bit Waveform is 4 bits long with 1/8 bit width pulse. Please refer to the diagram

below:

1 /8 bit w idth=128

α

4 bits w idth=40 96

α

Note: 1 bit=1024

α