THREE-PHASE WAVEFORM MODE
10.4 Three-phase mode 1
10.4.2 Operation in three-phase mode 1
Figure 10.4.4 shows a triangular wave modulation output example (three-phase mode 1).
❈ When an underflow occurs in the timer A3 counter, a timer A3 interrupt request is generated;
simultaneously, the one-shot pulse outputs of timers A0 through A2 are started. Also, the contents
of the three-phase output polarity set buffer are transferred to the output polarity set toggle flip-flop,
and then, the contents of the three-phase output polarity set buffer are reversed.
❈ The contents of the output polarity set toggle flip-flop are reversed at each falling edge of the one-
shot pulse output of timer A0/A1/A2. Simultaneously, the one-shot pulse of the dead-time timer is
output.
❈ Each of the positive and negative waveform outputs is not allowed to become “L” level from “H” level
until the reversed signal of the one-shot pulse output of the dead-time timer rises.
Repeat procedures from ❈ through ❈ for the three-phase waveform output control.
In the case of three-phase mode 1, the value of timer Ai ( i = 0 through 2) and the value of timer Ai are
1
counted alternately. Immediately after the count start in timer Ai, however, the value of the timer Ai register
is counted twice in succession. (It is a limitation to the case immediately after the count start in timer Ai.)
At this time, the timer Ai’s one-shot pulse becomes the same length twice in succession, also. Figure
10.4.5 shows an output example at start of three-phase mode 1.
For the triangular wave modulation output model (for one period), see Figure 10.3.6.
7906 Group User’s Manual Rev.2.0
10-30
RENESAS [ RENESAS TECHNOLOGY CORP ]
