SH7041A datasheet(393/923 Pages) RENESAS

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Example of Complementary PWM Mode Setting Procedure: An example of the

complementary PWM mode setting procedure is shown in figure 12.38.

1.Clear bits CST3 and CST4 in the timer start register (TSTR) to 0, and halt timer counter

(TCNT) operation. Perform complementary PWM mode setting when TCNT3 and TCNT4 are

stopped.

2.Set the same counter clock and clock edge for channels 3 and 4 with bits TPSC2–TPSC0 and

bits CKEG1 and CKEG0 in the timer control register (TCR). Use bits CCLR2–CCLR0 to set

synchronous clearing only when restarting by a synchronous clear from another channel during

complementary PWM mode operation.

3.When performing brushless DC motor control, set bit BDC in the timer gate control register

(TGCR) and set the feedback signal input source and output chopping or gate signal direct

output.

4.Set the dead time in TCNT3.Set TCNT4 to H'0000.

5.Set only when restarting by a synchronous clear from another channel during complementary

PWM mode operation. In this case, synchronize the channel generating the synchronous clear

with channels 3 and 4 using the timer synchro register (TSYR).

6.Set the output PWM duty in the duty registers (TGR3B, TGR4A, TGR4B) and buffer registers

(TGR3D, TGR4C, TGR4D). Set the same initial value in each corresponding TGR.

7.Set the dead time in the dead time register (TDDR), 1/2 the carrier cycle in the carrier cycle

data register (TCDR) and carrier cycle buffer register (TCBR), and 1/2 the carrier cycle plus

the dead time in TGR3A and TGR3C.

8.Select enabling/disabling of toggle output synchronized with the PWM cycle using bit PSYE

in the timer output control register (TOCR), and set the PWM output level with bits OLSP and

OLSN.

9.Select complementary PWM mode in timer mode register 3 (TMDR3).Pins TIOC3A,

TIOC3B, TIOC3D, TIOC4A, TIOC4B, TIOC4C, and TIOC4D function as output pins. Do not

set in TMDR4.

10.Set enabling/disabling of PWM waveform output pin output in the timer output master enable

11.Set bits CST3 and CST4 in TSTR to 1 simultaneously to start the count operation.

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