Non-Overlapping Pulse Output; Figure 12.6 Non-Overlapping Pulse Output - Hitachi H8S/2628 Hardware Manual

12.4.5

Non-Overlapping Pulse Output

During non-overlapping operation, transfer from NDR to PODR is performed as follows:
• NDR bits are always transferred on PODR bits on compare match A.
• On compare match B, NDR bits are transferred only if their value is 0. Bits are not transferred
if their value is 1.
Figure 12.6 illustrates the non-overlapping pulse output operation.
Pulse
output
pin
Therefore, 0 data can be transferred ahead of 1 data by making compare match B occur before
compare match A. The NDR contents should not be altered during the interval between compare
match B and compare match A (the non-overlap margin).
This can be accomplished by having the TGIA interrupt handling routine write the next data in
NDR, or by having the TGIA interrupt activate the DTC. Note, however, that the next data must
be written before the next compare match B occurs.
Figure 12.7 shows the timing of this operation.
Rev. 1.0, 09/02, page 276 of 568
DDR NDER
Q
Normal output/inverted output

Figure 12.6 Non-Overlapping Pulse Output

Q
C
PODR D Q
Compare match A
Compare match B
Internal data bus
NDR D