Datasheet

Section 12 Programmable Pulse Generator (PPG)
R01UH0309EJ0500 Rev. 5.00 Page 813 of 1408
Sep 24, 2012
H8S/2456, H8S/2456R, H8S/2454 Group
12.4.4 Non-Overlapping Pulse Output
During non-overlapping operation, transfer from NDR to PODR is performed as follows:
• NDR bits are always transferred to PODR bits at compare match A.
• At 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.
Compare match A
Compare match B
Pulse
output
pin
Internal data bus
Normal output/inverted output
C
PODRQD
NDER
Q
NDRQ D
DDR
Figure 12.6 Non-Overlapping Pulse Output
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 or DMAC. 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.