SH7243 datasheet(592/1726 Pages) RENESAS

592 / 1726 page

Section 11 Multi-Function Timer Pulse Unit 2 (MTU2)

Rev. 1.00 Jun. 26, 2008 Page 562 of 1692

REJ09B0393-0100

(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 11.56 Registers and Counters Requiring Initialization

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.

SH7243 Datasheet(PDF) 592 Page - Renesas Technology Corp