Non-Modulated Codes; Block Diagram Of Timers In Ir-Generation Mode; Modulated Waveform Example - Texas Instruments CC253x User Manual

IR Signal Generation and Learning
Timer 3 Ch 0 Compare
Figure 9-7. Block Diagram of Timers in IR-Generation Mode
The timing of the Timer 3 channel 1 output and Timer 1 channel 1 output signals is synchronized such that
no glitches are produced on the IR Out signal.
When the IRGEN bit is set, the IR out signal is routed to pins instead of the normal Timer 1 channel 1
output (see also Section
Figure 9-8 shows the example of Timer 3 being initialized to a 33% duty cycle (T3CC0 = 3 × T3CC1).
Timer 1 has been initialized to 3.
Timer 3 Output
Timer 1 Output
To achieve a period of space only, T1CC1 should be set to 0x00.

9.9.3 Non-Modulated Codes

To generate non-modulated IR codes, Timer 1 is used in modulo mode. The period of the signal is given
by T1CC0, and the pulse duration is given by T1CC1. T1CC1 gives the length of the mark period, and
T1CC0 gives the total number of mark and space periods. The compare values are buffered until the timer
hits 0x0000. The compare values must be updated once every period by the DMA or CPU if they are not
to be kept the same.
112
Timer 1 (16-Bit Timer)
Timer 3
Timer 1
7.6.1).
IR Out
Figure 9-8. Modulated Waveform Example
Copyright © 2009–2014, Texas Instruments Incorporated
Timer 3 Ch 1 Output
AND
Gate
Timer 1 Ch 1 Output
SWRU191F – April 2009 – Revised April 2014
www.ti.com
IR OUT
B0358-01
T0440-01
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