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Section 11 Multi-Function Timer Pulse Unit 2
Page 562 of 2108 R01UH0134EJ0400 Rev. 4.00
Sep 24, 2014
SH7262 Group, SH7264 Group
(n) Output Waveform Control at Synchronous Counter Clearing in Complementary PWM
Mode
Setting the WRE bit in TWCR to 1 suppresses initial output when synchronous counter clearing
occurs in the Tb interval at the trough in complementary PWM mode and controls abrupt change
in duty cycle at synchronous counter clearing.
Initial output suppression is applicable only when synchronous clearing occurs in the Tb interval
at the trough as indicated by (10) or (11) in figure 11.56. When synchronous clearing occurs
outside that interval, the initial value specified by the OLS bits in TOCR is output. Even in the Tb
interval at the trough, if synchronous clearing occurs in the initial value output period (indicated
by (1) in figure 11.56) immediately after the counters start operation, initial value output is not
suppressed.
When using the initial output suppression function, make sure to set compare registers TGRB_3,
TGRA_4, and TGRB_4 to a value twice or more the setting of dead time data register TDDR. If
synchronous clearing occurs with the compare registers set to a value less than twice the setting of
TDDR, the PWM output dead time may be too short (or nonexistent) or illegal active-level PWM
negative-phase output may occur during the initial output suppression interval. For details, see
section 11.7.23, Notes on Output Waveform Control During Synchronous Counter Clearing in
Complementary PWM Mode.