SH7261 Datasheet, PDF (532/1348 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7260 Series

Section 12 Multi-Function Timer Pulse Unit 2 (MTU2)
(c) Initialization
In complementary PWM mode, there are six registers that must be initialized. In addition, there is
a register that specifies whether to generate dead time (it should be used only when dead time
generation should be disabled).
Before setting complementary PWM mode with bits MD3 to MD0 in the timer mode register
(TMDR), the following initial register values must be set.
TGRC_3 operates as the buffer register for TGRA_3, and should be set with 1/2 the PWM carrier
cycle + dead time Td. The timer cycle buffer register (TCBR) operates as the buffer register for
the timer cycle data register (TCDR), and should be set with 1/2 the PWM carrier cycle. Set dead
time Td in the timer dead time data register (TDDR).
When dead time is not needed, the TDER bit in the timer dead time enable register (TDER) should
be cleared to 0, TGRC_3 and TGRA_3 should be set to 1/2 the PWM carrier cycle + 1, and TDDR
should be set to 1.
Set the respective initial PWM duty values in buffer registers TGRD_3, TGRC_4, and TGRD_4.
The values set in the five buffer registers excluding TDDR are transferred simultaneously to the
corresponding compare registers when complementary PWM mode is set.
Set TCNT_4 to H'0000 before setting complementary PWM mode.
Table 12.56 Registers and Counters Requiring Initialization
Register/Counter
Set Value
TGRC_3
1/2 PWM carrier cycle + dead time Td
(1/2 PWM carrier cycle + 1 when dead time generation
is disabled by TDER)
TDDR
Dead time Td (1 when dead time generation is
disabled by TDER)
TCBR
1/2 PWM carrier cycle
TGRD_3, TGRC_4, TGRD_4
Initial PWM duty value for each phase
TCNT_4
H'0000
Note: The TGRC_3 set value must be the sum of 1/2 the PWM carrier cycle set in TCBR and
dead time Td set in TDDR. When dead time generation is disabled by TDER, TGRC_3
must be set to 1/2 the PWM carrier cycle + 1.
Rev. 2.00 Sep. 07, 2007 Page 500 of 1312
REJ09B0320-0200