M16C65 Datasheet, PDF (413/829 Pages) Renesas Technology Corp – RENESAS MCU M16C FAMILY / M16C/60

Under development
M16C/65 Group
Preliminary Specification
This is a preliminary specification and is subject to change.
19. Three-Phase Motor Control Timer Function
19.3 Operations
19.3.1 Common Operations in Multiple Modes
19.3.1.1 Carrier Wave Cycle Control
Timer B2 controls the cycle of the carrier wave. In triangular wave modulation mode, the cycle of the
carrier wave is double the cycle of timer B2 underflow. In sawtooth wave modulation mode, the cycle
of carrier wave equals to the cycle of timer B2 underflow. Figure 19.3 shows Relationship between
Carrier Wave Cycle and Timer B2.
Timer B2 underflow is a start trigger for timers A1, A2, and A4, which control the three-phase PWM
waveform. However, when the INV10 bit in the INVC1 register is 1, writing to the TB2 register also
generates a trigger for timers A1, A2, and A4.
The frequency of timer B2 interrupt requests can be selected for three-phase motor control timers.
In triangular wave modulation three-phase mode 0 and sawtooth wave modulation mode, when a
setting value in the ICTB2 register is n, the timer B2 interrupt request is generated every nth count of
timer B2 underflow.
In triangular wave modulation three-phase mode 1, when a setting value in the ICTB2 register is n, a
timer B2 interrupt request is generated every nth time of the timing selected by bits INV01 and INV00
in the INVC1 register. However, when bits INV01 and INV00 are 11b, the first interrupt is generated at
the n-1th time of timer B2 underflow.
Triangular wave
Carrier wave
Signal wave
Sawtooth wave
Carrier wave
Signal wave
Cycle of timer B2
Timer B2 underflow signal
Timer A1, A2 or A4
one-shot pulse
Figure 19.3 Relationship between Carrier Wave Cycle and Timer B2
REJ09B0484-0030 Rev.0.30 Sep 09, 2008
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