HD643303x Hitachi, HD643303x Datasheet - Page 247

• Manufacturer Part Number: HD643303x
• Description: Hitachi Microcomputer
• Manufacturer: Hitachi

Examples of Complementary PWM Mode: Figure 8-35 shows an example of operation in
complementary PWM mode. TCNT3 and TCNT4 operate as up/down-counters, counting down
from compare match between TCNT3 and GRA3 and counting up from the point at which
TCNT4 underflows. During each up-and-down counting cycle, PWM waveforms are generated by
compare match with general registers GRB3, GRA4, and GRB4. Since TCNT3 is initially set to a
higher value than TCNT4, compare match events occur in the sequence TCNT3, TCNT4, TCNT4,
TCNT3.
GRA3
GRB3
GRA4
GRB4
H'0000
TIOCA3
TIOCB3
TIOCA4
TOCXA4
TIOCB4
TOCXB4
TCNT3 and
TCNT4 values
Figure 8-35 Operation in Complementary PWM Mode (Example 1)
TCNT4
(when OLS3 = OLS4 = 1)
Down-counting starts at compare
match between TCNT3 and GRA3
232
Up-counting starts when
TCNT4 underflows
TCNT3
Time