Renesas RX100 Series User Manual page 427

Hide thumbs Also See for RX100 Series:

Table of Contents

(2) Outline of Complementary PWM Mode Operation

In complementary PWM mode, six phases (three positive and three negative) PWM waveforms can be output. Figure

19.46 illustrates counter operation in complementary PWM mode (MTU3 and MTU4), and Figure 19.47 shows an

example of operation in complementary PWM mode.

(a) Counter Operation

In complementary PWM mode, three counters—MTU3.TCNT, MTU4.TCNT, and TCNTSA —in each unit perform up-

/down-count operations.

MTU3.TCNT is automatically initialized to the value set in TDDRA when complementary PWM mode is selected and

the CST3 bit in TSTRA is 0. When the CST3 bit is set to 1, MTU3.TCNT counts up to the value set in MTU3.TGRA,

then switches to down-counting when it matches MTU3.TGRA. When the MTU4.TCNT value matches 0000h,

MTU3.TCNT switches to up-counting, and the operation is repeated in this way.

MTU4.TCNT should be initialized to 0000h after a reset. When the CST4 bit is set to 1, MTU4.TCNT counts up in

synchronization with MTU3.TCNT, and switches to down-counting when MTU3.TCNT matches MTU3.TGRA. On

reaching 0000h, MTU4.TCNT switches to up-counting, and the operation is repeated in this way. TCNTSA is a read-

only counter. It does not need to be initialized after a reset.

In counting up by MTU3.TCNT and MTU4.TCNT, MTU3.TCNT starts counting up when it matches TCDRA and

switches to counting down when it matches MTU3.TGRA. Furthermore, when MTU4.TCNT matches TDDRA,

TCNTSA is set to the value in MTU3.TGRA and counting is stopped.

When MTU4.TCNT matches TDDRA during down-counting of MTU3.TCNT and MTU4.TCNT, TCNTSA starts up-

counting, and when MTU4.TCNT matches 0000h, the operation switches to down-counting. When MTU3.TCNT

matches TCDRA, TCNTSA becomes 0000h and stops counting.

TCNTSA is compared with the compare register and temporary register, in which the PWM duty is specified, only

during the count operation.

Counter value

Figure 19.46

Count Operation in Complementary PWM Mode (MTU3 and MTU4)

R01UH0822EJ0100 Rev.1.00

Jul 31, 2019

19. Multi-Function Timer Pulse Unit 3 (MTU3c)

Page 427 of 1041