Abov MC96F6432S Series, Руководство пользователя

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149
MC96F6432S ABOV Semiconductor Co., Ltd.
Phase correction & Frequency correction
On operating PWM, it is possible that it is changed the phase and the frequency by using BMOD bit (back-to-back
mode) in T4PCR1 register. (Figure 1.38, Figure 11.39, Figure 11.40 referred)
In the back-to-back mode, the counter of PWM repeats up/down count. In fact, the effective duty and period becomes
twofold of the register set values. (Figure 1.38, Figure 11.39 referred)
Figure 11.38 Example of PWM Output Waveform
Figure 11.39 Example of PWM waveform in Back-to-Back mode at 4 MHz
T4CNT
00 01 02 03 04
P02/PWM4AA
POLAA = 1
T4CR = 03
H
(2 us)
T4PPRH = 00
H
T4PPRL = 0B
H
T4ADRH = 00
H
T4ADRL = 05
H
09 08 07 06 05
0A 0B 0B 0A 06 07 08 09 02 03 04 05 01 00 00 01 05 04 03 02 07 06
Source Clock
(f
X
)
08
Duty Cycle
(1+05
H
)X2 us = 12 us
Duty Cycle
(1+05
H
)X2 us = 12 us
Duty Cycle
(1+05
H
)X2 us = 12 us
Period Cycle
(1+0B
H
)X2 us = 26 us

38.46 kHz
Start down Counter
Period Cycle
(1+0B
H
)X2 us = 26 us

38.46 kHz
Duty match
detect
Start up Counter
Duty match
detect
T4CNT
Duty
Normal PWM
mode
Output
00
H
00
H
00
H
00
H
00
H
MAX
MAX
MAX
MAX
Period
Duty, Period
Update
T4CNT
Duty
Back-to-Back
mode
Output
00
H
00
H
00
H
MAX
MAX
MAX
Period
Duty, Period
Update
Duty
Period
Non Back-to-Back mode
Back-to-Back mode