Hitachi H8S/2378, H8S/2378R Series Hardware Manual page 593

Examples of Phase Counting Mode Operation: In phase counting mode, TCNT counts up or
down according to the phase difference between two external clocks. There are four modes,
according to the count conditions.
1. Phase counting mode 1
Figure 11.25 shows an example of phase counting mode 1 operation, and table 11.32
summarizes the TCNT up/down-count conditions.
TCLKA (channels 1 and 5)
TCLKC (channels 2 and 4)
TCLKB (channels 1 and 5)
TCLKD (channels 2 and 4)
TCNT value
Figure 11.25 Example of Phase Counting Mode 1 Operation
Table 11.32 Up/Down-Count Conditions in Phase Counting Mode 1
TCLKA (Channels 1 and 5)
TCLKC (Channels 2 and 4)
High level
Low level
High level
Low level
Legend
: Rising edge
: Falling edge
Up-count
TCLKB (Channels 1 and 5)
TCLKD (Channels 2 and 4)
Low level
High level
High level
Low level
Down-count
Operation
Up-count
Down-count
Rev. 1.0, 09/01, page 549 of 904
Time