AN2957 Datasheet, PDF (4/21 Pages) STMicroelectronics – Implementing an RC5 infrared transmitter

RC5 coding scheme
2
RC5 coding scheme
AN2957
The RC5 coding scheme from Philips is a standard in infrared wireless command
transmission.
The RC5 coding scheme can generate 2048 different commands organized on 32 groups,
each group has 64 different commands.
The RC5 frame is a 14-bit word, composed of 3 parts:
● Header (3 bits)
● Device Address (5 bits)
● Device Instruction (6 bits)
The bits are transmitted in bi-phase code (also known as Manchester code) as shown in
Figure 3.
The RC5 carrier frequency is 36 kHz.
Figure 2. RC5 frame format
Header (3 bits)
Device address (5 bits) Device instruction (6 bits)
Figure 3. Manchester coding
Logic 0
Logic 1
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Doc ID 15550 Rev 2