M30222 Datasheet, PDF (99/237 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

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MITSUBISHI MICROCOMPUTERS
Specifications in this manual are tentative and subject to change
M30222 Group
Rev. G
Timer Functions For Three-phase Motor Control
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
finishes outputting one-shot pulses, "0" already shifted in the three-phase shift register goes effective,
and the U phase waveform changes to the "L" level. When the Timer B2 counter’s content becomes
000016, the Timer A4 counter starts counting the value written to Timer A4-1 (034716, 034616), and
starts outputting one-shot pulses. When Timer A4 finishes outputting one-shot pulses, the three-
phase shift register’s content is shifted one position, but if the three-phase output shift register’s con-
tent changes from “0” to “1” as a result of the shift, the output level changes from “L” to “H” without
waiting for the timer for setting dead time to finish outputting one-shot pulses. A U phase waveform is
generated by these workings repeatedly. With the exception that the three-phase output shift register
on the U phase side is used, the workings in generating a U phase waveform, which has the opposite
phase of the U phase waveform, are the same as in generating a U phase waveform. In this way, a
waveform can be picked up from the applicable terminal in a manner in which the "L" level of the U
phase waveform doesn’t lap over that of the U phase waveform, which has the opposite phase of the
U phase waveform. The width of the “L” level too can be adjusted by varying the values of Timer B2,
Timer A4, and Timer A4-1. In dealing with the V and W phases, and V and W phases, the latter are of
opposite phase of the former, have the corresponding timers work similarly to dealing with the U and
U phases to generate an intended waveform.
A carrier wave of triangular waveform
Carrier wave
Signal wave
Timer B2
Trigger signal for
Timer Ai start
(Timer B2 overflow
signal)
Timer B2 interrupt occurs
Rewriting Timer A4 and Timer A4-1.
Possible to set the number of overflows to generate an
interrupt by use of the interrupt occurrences frequency
set circuit
Timer A4 output
m
n
m
n
m
p
o
Control signal for
Timer A4 reload
U phase
output signal
U phase
output signal
U phase
U phase
Dead time
Note: Set to Triangular wave modulation mode and to Three-phase mode 1.
Fig. 1.74. Timing chart operation (1)
1-100
The Three-phase
shift register
shifts in
synchronization
with the falling
edge of the A4
output.