9 Remote control protocols

STFPC311

26/39

9.2

SPI interface IR data transmission

The IR data is sent on the DOUT pin of the SPI interface when the micro controller issues a IR

data read command. The data is sent in 3 bytes with LSB transmitted first as shown in the

Figure below:

The RC data consists of RC address, start bit, toggle bit and the RC command received. The

extra bits are stuffed with 1’s to make it a 3-byte packet. These extra bits at the end of the

packet should be ignored.

Figure 24. RC-6 protocol frame

The RC data consists of RC address, start bit, toggle bit and the RC command received. The

extra bits are stuffed with 1’s to make it a 3-byte packet. These extra bits at the end of the

packet should be ignored.

9.3

NEC remote control

This remote control protocol uses pulse distance modulation. Each bit consists of a high level of

fixed time "t", followed by a low level that varies in width. A space that is "t" represents a logic '0'

and a space that is "3t" represents a logic '1'. t = 0.56ms.

The LSB is transmitted first as shown in Figure 25

Figure 25. Pulse distance modulation.