The carrier modulator timer (CMT) module provides a means to generate the protocol timing and carrier signals for a variety of encoding schemes. The CMT does not include dedicated hardware configurations for specific protocols but is intended to be sufficiently programmable in its function to handle the timing requirements of most protocols with minimal CPU intervention.

The CMT consist of a carrier generator, modulator and transmitter which drives the infrared output pin. Modulation cycle consist of two parts: Mark and space.

The features of the CMT module:

• Four Operation modes: Time, Baseband, FSK, Direct SW control of output pin.
• Extended space operation.
• Interrupt event on end of modulation cycle.

Following picture illustrates an example of output signal in Time and Baseband mode.

Following picture illustrates an example of output signal in FSK mode.

Following picture illustrates an example of output signal in extended space operation.