Usage Notes - Hitachi H8S/2646 Hardware Manual

Hitachi 16-bit single-chip microcomputer h8s/2646 series
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11.4

Usage Notes

Operation of Pulse Output Pins: Pins PO8 to PO15 are also used for other peripheral functions
such as the TPU. When output by another peripheral function is enabled, the corresponding pins
cannot be used for pulse output. Note, however, that data transfer from NDR bits to PODR bits
takes place, regardless of the usage of the pins.
Pin functions should be changed only under conditions in which the output trigger event will not
occur.
Note on Non-Overlapping Output: During non-overlapping operation, the transfer of NDR bit
values to PODR bits takes place 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 11-10 illustrates the non-overlapping pulse output operation.
DDR
Pulse
output
pin
410
NDER
Q
C
Q
PODR
Normal output/inverted output
Figure 11-10 Non-Overlapping Pulse Output
D
Q
NDR
Compare match A
Compare match B
D
Internal data bus

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