Hitachi H8S/2646 Hardware Manual page 443

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 from compare
match B to 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 11-11 shows the timing of this operation.
Compare match A
Compare match B
NDR
PODR
Figure 11-11 Non-Overlapping Operation and NDR Write Timing
Write to NDR
0 output 0/1 output
Write to NDR
here
Do not write
to NDR here
Write to NDR
0 output 0/1 output
Write to NDR
here
Do not write
to NDR here
411