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PT2272 V3.7

- 10 -

June, 2008

Remote Control Decoder

PT2272

VALID TRANSMISSION

When PT2272 receives a transmission code word, it initially checks whether this is a valid transmission.

For a transmission to be valid, (1) it must be a Complete Code Word, and (2) the Address Bits must

match the Address Setting at the Address Pins. After two consecutive valid transmissions, PT2272 (1)

drives the data pins according to the data bits received, and (2) raises VT to high voltage (high state).

The timings are shown in the following diagram.

Sync bit

1st word

2nd word

Sync bit

DIN

Data pins

(momentary)

VT

ta = 8 OSC clock width

tb = 1 OSC clock width

tc = 2 code word width

LATCH OR MOMENTARY DATA OUTPUT TYPE

PT2272 uses either the latch or the momentary data output type depending on the PT2272 version

used. The latch type (PT2272-Lx) activates the data out during transmission and this data is sustained

in the memory until another data is inputted or entered. A momentary type (PT2272-Mx), on the other

hand, activates the data out only during transmission. In the momentary type, the data does not remain

in the memory after the transmission is completed. Please refer to the diagram below:

T

T

DATA WORDS

DATA WORDS

DATA OUTPUT X

DATA OUTPUT Y

DATA OUTPUT X

DATA OUTPUT Y

DIN

DATA PINS

(Momentary)

DATA PINS

(Latch)

VT

T = 2 CODE WORDS WIDTH