THREE-PHASE WAVEFORM MODE
7905 Group User’s Manual Rev.1.0
10-2
10.1 Overview
The three-phase waveform mode serves as follows: three-phase waveforms (3 positive waveforms and 3
negative waveforms) are output from the three-phase waveform output pins. The three-phase waveform
mode consists of “three-phase mode 0” and “three-phase mode 1.”
Table 10.1.1 lists the specifications of the three-phase waveform mode, Table 10.1.2 lists the comparison
of operations in three-phase mode 0 and 1, and Figure 10.1.1 shows the comparison of waveforms in three-
phase mode 0 and 1.
Table 10.1.1 Specifications of three-phase waveform mode
Table 10.1.2 Comparison of operations in three-phase mode 0 and 1
6 pins (U, U, V, V, W, W)
P6OUTCUT (Input of falling edge)
Three-phase mode 0 A timer A3 interrupt request occurs at each timer A3 underflow.
Three-phase mode 1
A timer A3 interrupt request occurs at each second timer A3
underflow or forth one.
Timers A0 through A2 (Used in the one-shot pulse mode)
Timer A0 : W- and W-phase waveform control
Timer A1 : V- and V-phase waveform control
Timer A2 : U- and U-phase waveform control
Timer A3 (Used in the timer mode)
Output period control
Saw-tooth-wave mo-
dulation output
Triangular wave mo-
dulation output
Fixed level output
Dead-time timer is used.
See Table 10.2.1.
Item
Specifications
Three-phase waveform output pins
Three-phase-waveform-output-
forcibly-cutoff signal input pin
Operation modes
Timer to be used
Three-phase waveform
period
Output waveform and
Output width
Dead time (width)
2 to
65535 2 (Note)
1
f1
1
f4096
to
65535 (Note)
1
f1
1
f4096
to
65536
1
f1
1
f4096
Each of the U, V, W phases is fixed to an arbitrary level.
Each of the U, V, W phases is fixed to the reversed level of the
corresponding positive phase (the U, V, W phases).
Note: This value does not include the dead time.
Each timer A3 underflow
Each timer uses one register.
By software, the output polarity can be set to the
output polarity set buffer of the U, V, or W phases.
If necessary, the contents of each output
polarity set buffer are reversed by software.
Three-phase mode 0
Three-phase mode 1
Timer A3 interrupt request
occurrence interval
Timers A0 through A2
Output polarity
Each second timer A3 underflow or forth
one is selected by software.
Each timer uses two registers alternately.
By software, the output polarity can be set
to the three-phase output polarity set buffer.
At each period, the contents of the three-
phase output polarity set buffer are reversed
by hardware.
10.1 Overview