R01UH0822EJ0100 Rev.1.00
Page 423 of 1041
Jul 31, 2019
RX13T Group
19. Multi-Function Timer Pulse Unit 3 (MTU3c)
19.3.8
Complementary PWM Mode
In complementary PWM mode, dead time can be set for PWM waveforms to be output. The dead time is the period
during which the upper and lower arm transistors are set to the inactive level in order to prevent short-circuiting of the
arms.
Six positive-phase and three negative-phase PWM waveforms (six phases in total) with dead time can be output by
combining MTU3/ MTU4. PWM waveforms without dead time can also be output.
In complementary PWM mode, MTIOC3B, MTIOC3D, MTIOC4A, MTIOC4B, MTIOC4C, and MTIOC4D pins
function as PWM output pins, and the MTIOC3A pin can be set for toggle output synchronized with the PWM period.
MTU3.TCNT and MTU4.TCNT function as up/down-counters.
shows the PWM output pins used.
shows the settings of the registers used.
A function to directly cut off the PWM output by using an external signal is supported as a port function.
Note 1. Avoid setting the MTIOC3C pin as timer I/O pins in complementary PWM mode.
Note 1. Access can be enabled or disabled according to the setting in TRWERA (timer read/write enable register A).
Table 19.58
Output Pins for Complementary PWM Mode
Channel
Output Pin
Description
MTU3
MTIOC3A
Toggle output synchronized with PWM period (or I/O port)
MTIOC3B
PWM output pin 1
MTIOC3C
I/O port*
1
MTIOC3D
PWM output pin 1' (negative-phase waveform output of PWM output 1)
MTU4
MTIOC4A
PWM output pin 2
MTIOC4C
PWM output pin 2' (negative-phase waveform output of PWM output 1)
MTIOC4B
PWM output pin 3
MTIOC4D
PWM output pin 3' (negative-phase waveform output of PWM output 1)
Table 19.59
Register Settings for Complementary PWM Mode (1/2)
Channel
Counter/ Register Description
Read/Write from CPU
MTU3
TCNT
Starts up-counting from the value set in the dead time
register
Maskable by TRWERA setting*
TGRA
Set MTU3.TCNT upper limit value (1/2 carrier
dead time)
Maskable by TRWERA setting*
TGRB
PWM output 1 compare register
Maskable by TRWERA setting*
TGRC
MTU3.TGRA buffer register
Readable/writable
TGRD
PWM output 1/MTU3.TGRB buffer register
Readable/writable
TGRE
MTU3.TGRB buffer register B (when double buffer function
is used)
Readable/writable
MTU4
TCNT
Starts up-counting after being initialized to 0000h
Maskable by TRWERA setting*
TGRA
PWM output 2 compare register
Maskable by TRWERA setting*
TGRB
PWM output 3 compare register
Maskable by TRWERA setting*
TGRC
PWM output 2/MTU4.TGRA buffer register
Readable/writable
TGRD
PWM output 3/MTU4.TGRB buffer register
Readable/writable
TGRE
MTU4.TGRA buffer register B (when double buffer function
is used)
Readable/writable
TGRF
MTU4.TGRB buffer register B (when double buffer function
is used)
Readable/writable