Datasheet

78K0/Ix2 CHAPTER 9 8-BIT TIMER H1
R01UH0010EJ0500 Rev.5.00 350
Feb 28, 2012
9.4.3 Carrier generator operation
In the carrier generator mode, the 8-bit timer H1 is used to generate the carrier signal of an infrared remote controller,
and the 8-bit timer/event counter 51 is used to generate an infrared remote control signal (time count).
The carrier clock generated by the 8-bit timer H1 is output in the cycle set by the 8-bit timer/event counter 51.
In carrier generator mode, the output of the 8-bit timer H1 carrier pulse is controlled by the 8-bit timer/event counter 51,
and the carrier pulse is output from the TOH1 output.
(1) Carrier generation
In carrier generator mode, the 8-bit timer H compare register 01 (CMP01) generates a low-level width carrier pulse
waveform and the 8-bit timer H compare register 11 (CMP11) generates a high-level width carrier pulse waveform.
Rewriting the CMP11 register during the 8-bit timer H1 operation is possible but rewriting the CMP01 register is
prohibited.
(2) Carrier output control
Carrier output is controlled by the interrupt request signal (INTTM51) of the 8-bit timer/event counter 51 and the
NRZB1 and RMC1 bits of the 8-bit timer H carrier control register (TMCYC1). The relationship between the outputs is
shown below.
RMC1 Bit NRZB1 Bit Output
0 0 Low-level output
0 1
High-level output at rising edge of
INTTM51 signal input
1 0 Low-level output
1 1
Carrier pulse output at rising edge of
INTTM51 signal input