MITSUBISHI MICROCOMPUTERS
M37754M8C-XXXGP, M37754M8C-XXXHP
M37754S4CGP, M37754S4CHP
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
The U-phase waveform output keeps “H” level from the start until the
one-shot pulse output of the dead-time timer is completed, even if
the contents of output polarity set toggle flip-flop 2 are reversed from
“0” to “1” owing to the timer A2’s one-shot pulse output.
When the one-shot pulse output of the dead-time timer is completed,
“1” of output polarity set toggle flip-flop 2 which has been reversed
becomes valid and the U-phase waveform changes to “L” level.
Then, when the counter of timer B2 becomes 000016, the timer A2
counter counts the value written into timer A2 and timer A2 starts
one-shot pulse output. Simultaneously, the contents of three-phase
output polarity set buffer are set into the output polarity set toggle
flip-flop 2. However, the U-phase waveform remains “L” level, be-
cause the value is the same (“1”).
The contents of three-phase output polarity set buffer are reversed
from “1” to “0” after that operation.
When the one-shot pulse output of timer A2 is completed, the con-
tents of output polarity set toggle flip-flop 2 is reversed from “1” to “0”.
Simultaneously, the one-shot pulse output of the dead-time timer
starts.
When the contents of output polarity set toggle flip-flop 2 is reversed
from “1” to “0”, the U-phase waveform changes its output level from
“L” to “H” without waiting for completion of the one-shot pulse output
of the dead-time timer.
U-phase waveform is generated by repeating the operation above.
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The way to generate U-phase waveform, which is the negative
phase of U-phase, is the same as that for U-phase waveform except
that the contents of output polarity set toggle flip-flop 2 is treated as
the reversed signal from the case of U-phase waveform.
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In this way, U-phase waveform and U-phase waveform, having the
negative phase of U-phase, are output from the pins so that their “L”
levels do not overlap each other. The width of “L” level can be also
modified by changing the value of timer B2, timer A2 or timer A21.
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V-, W-phase waveform and V-, W-phase waveform, having their
negative phase, are similarly output according to the corresponding
timer operation.
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RENESAS [ RENESAS TECHNOLOGY CORP ]
