
HITACHI 265
Table 10.14 Output Pins for Complementary PWM Mode
Channel
Output Pin
Description
3
TIOCA3
PWM output 1
TIOCB3
PWM output 1' (non-overlapping negative-phase waveform of
PWM output 1)
4
TIOCA4
PWM output 2
TOCXA4
PWM output 2' (non-overlapping negative-phase waveform of
PWM output 2)
TIOCB4
PWM output 3
TOCXB4
PWM output 3' (non-overlapping negative-phase waveform of
PWM output 3)
Table 10.15 Register Settings for Complementary PWM Mode
Register
Description of Contents
TCNT3
Initial setting of non-overlap cycle (the difference with TCNT4)
TCNT4
Initial setting of H'0000
GRA3
Set upper limit of TCNT3–1
GRB3
Sets the turning point for PWM waveform output by the TIOCA3 and TIOCB3 pins.
GRA4
Sets the turning point for PWM waveform output by the TIOCA4 and TOCXA4 pins.
GRB4
Sets the turning point for PWM waveform output by the TIOCB4 and TOCXB4 pins.
Procedure for Selecting the Complementary PWM Mode (figure 10.33):
1. Clear STR3 and STR4 bits in the TSTR to halt the timer counters. The complementary PWM
mode must be set up while TCNT3 and TCNT4 are halted.
2. Set bits TPSC2–TPSC0 in the TCR to select the same counter clock source for channels 3 and
4. If an external clock source is selected, select the external clock edges with bits CKEG1 and
CKEG0 in the TCR. Do not select any counter clear source with bits CCLR1 and CCLR0 in
the TCR.
3. Set bits CMD1 and CMD0 in TMDB to select the complementary PWM mode. TIOCA3–
TIOCB4, TOCXA4, and TOCXB4 automatically become PWM pins.
4. Reset TCNT4 (to H'0000). Set the non-overlap offset in TCNT3. Do not set TCNT3 and
TCNT4 to the same value.