HD643303x Hitachi, HD643303x Datasheet - Page 253

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

Output pin
Output pin
— General register settings outside the counting range (H'0000 to GRA3)
H'0000
Figure 8-42 Changing a General Register Setting by Buffer Transfer (Example 2)
GRA3
Waveforms with a duty cycle of 0% or 100% can be output by setting a general register to
a value outside the counting range. When a buffer register is set to a value outside the
counting range, then later restored to a value within the counting range, the counting
direction (up or down) must be the same both times. See figure 8-42.
Settings can be made in this way by detecting GRA3 compare match or TCNT4
underflow before writing to the buffer register.
GR
GR
BR
Write during down-counting
0% duty cycle
238
Write during up-counting
100% duty cycle