Hitachi H8/3035 Series Hardware Manual page 261

Note on Synchronous Preset: When channels are synchronized, if a TCNT value is modified by
byte write access, all 16 bits of all synchronized counters assume the same value as the counter
that was addressed.
(Example) When channels 2 and 3 are synchronized
• Byte write to channel 2 or byte write to channel 3
TCNT2 W
TCNT3 Y
Upper byte Lower byte
• Word write to channel 2 or word write to channel 3
TCNT2 W
TCNT3 Y
Upper byte Lower byte
Note on Setup of Reset-Synchronized PWM Mode and Complementary PWM Mode: When
setting bits CMD1 and CMD0 in TFCR, take the following precautions:
• Write to bits CMD1 and CMD0 only when TCNT3 and TCNT4 are stopped.
• Do not switch directly between reset-synchronized PWM mode and complementary PWM
mode. First switch to normal mode (by clearing bit CMD1 to 0), then select reset-
synchronized PWM mode or complementary PWM mode.
Write A to upper byte
of channel 2
X
Z
Write A to lower byte
of channel 3
X
Write AB word to
Z
channel 2 or 3
TCNT2 A
TCNT3 A
Upper byte Lower byte
TCNT2 Y
TCNT3 Y
Upper byte Lower byte
TCNT2 A
TCNT3 A
Upper byte Lower byte
X
X
A
A
B
B
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