Renesas M16C/29 Series Hardware Manual page 146

M16C/29 Group
The three-phase motor control timer function is enabled by setting the INV02 bit of INVC0 register to "1".
When this function is on, timer B2 is used to control the carrier wave, and timers A4, A1 and A2 are used
to control three-phase PWM outputs (U, U, V, V, W and W). The dead time is controlled by a dedicated
dead-time timer. Figure 12.3.9 shows the example of triangular modulation waveform, and Figure 12.3.10
shows the example of sawtooth modulation waveform.
Carrier wave
Signal wave
TB2S bit of the
TABSR register
Timer B2
Start trigger signal
for timer A4*
Timer A4
one-shot pulse*
U phase
output signal *
U phase
output signal *
U phase
INV14 = 0
("L" active)
U phase
U phase
INV14 = 1
("H" active)
U phase
INV13
(INV11=1(three-phase
mode 1))
* Internal signals. See the block diagram of the three-phase motor control timer function.
Shown here is a typical waveform for the case where INVC0 = 00XX11XX
An example for changing PWM outputs is shown below.
(1)When INV11=1(three-phase mode 1)
· INV01=0, ICTB2=2 (timer B2 interrupt is generated at every 2'th
16
occurrence of a timer B2 underflow), or INV01=1, INV00=1,
ICTB2=1 (timer B2 interrupt is generated at even-numbered
16
occurrences of a timer B2 underflow).
· Initial timer value: TA41=m, TA4=m. The TA4 and TA41 registers
are modified every time a timer B2 interrupt occurs. First time,
TA41= n, TA4 = n. Second time, TA41 = p, TA4 = p.
· Initial values of IDB0 and IDB1 registers: DU0 = 1, DUB0 = 0,
DU1 = 0, DUB1 = 1.The register values are changed to DU0 = 1,
DUB0 = 0, DU1= 1 and DUB1 = 0 the third time a timer B2
interrupt occurs.
The value written to the TA4 register and TA41 register are inverted at odd-numbered timer A outputs.
Figure 12.3.9. Triangular Wave Modulation Operation
Rev.1.00 Nov 01,2004
REJ09B0101-0100Z
m m
page 126 of 402
12.3 Three-phase Motor Control Timer Function
__ ___ ___
n n
Dead time
Dead time
(X = set as suitable for the system) and INVC1 = 010XXXX0
2
(2)When INV11=0(three-phase mode 0)
· INV01=0, ICTB2=1 (timer B2 interrupt is generated at every
16
occurrence of a timer B2 underflow)
· Initial timer value: TA4 = m. The TA4 register is modified each time
a timer B2 interrupt occurs. First time, TA4 = m. Second time, TA4 = n.
Third time, TA4 = n. Fourth time, TA4 = p. Fifth time, TA4 = p.
· Initial values of IDB0 and IDB1 registers: DU0=1, DUB0=0, DU1=0,
DUB1=1.The register values are changed to DU0 = 1, DUB0 = 0, DU1=
1 and DUB1 = 0 the sixth time a timer B2 interrupt occurs.
p
p
Rewriting IDB0, IDB1 registers
Transfer to three-phase
output shift register
.
2