STFPC320 datasheet(52/78 Pages) STMICROELECTRONICS

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Remote control protocols

STFPC320

52/78

15.3

Philips RC-5 remote control protocol

The RC-5 remote control protocol is based on bi-phase (aka Manchester) coding as shown

in Figure 25. Note that the coding is on the transmitted side. The data on IR_DATA_IN pin of

the STFPC320 after reception by the photo diode will be inverted of below. The MSB is

transmitted first.

Figure 25.

Bi-phase coding

Figure 26.

RC-5 protocol frame

Figure 27.

Example of RC-5 transmission

For RC 5 data transmission, a binary 1 is represented by a low to high transition and a

binary 0 is represented by a high to low transition from the IR transmitter.

The first two start bits (S1 and S2) are sync bits. For normal operation, they are always set

to “11” on the transmit side. After the photo-diode, there is one inversion. So the data at the

IR_DATA_IN of the STFPC320 will be inverted of above. The next bit is the toggle bit. This

bit is inverted each time a key on the remote control is pressed. Bits A1..A5 are the address

bits. The address bits indicate the intended application that the remote control protocol is

used for. Bits C1..C6 are the command bits. The command bits instruct what action is to be

taken.

Logic 1

Logic 0

1.776ms

Data word

114 ms

24.9 ms

2-bit Start

bits

1-bit

Toggle Bit

5-bit Address

6-bit Command

MSB

LSB MSB

LSB

Data word

STFPC320 Datasheet(PDF) 52 Page - STMicroelectronics