HD6417021 Hitachi Semiconductor, HD6417021 Datasheet - Page 287

• Manufacturer Part Number: HD6417021
• Description: SuperH RISC engine
• Manufacturer: Hitachi Semiconductor

Phase Counting Operation: Figure 10.43 shows an example of phase counting mode operation.
Table 10.16 lists the upcounting and downcounting conditions for TCNT2. The ITU counts on
both rise and fall edges of TCLKA and TCLKB. The phase differential and overlap of TCLKA
and TCLKB must be 1.5 cycles or more and the pulse width must be 2.5 cycles or more.
Table 10.16 Up/Down Counting Conditions
Counting
Direction
TCLKB
TCLKA
TCLKB
TCLKA
TCNT2 value
Figure 10.42 Procedure for Selecting the Phase Counting Mode
Increment
Rising
Low
Increment
Figure 10.43 Phase Counting Mode Operation
High
Rising
Select phase counting mode
Select flag setting condition
Phase counting mode
Phase counting mode
Falling
High
Start counting
Falling
Low
TCNT2
Decrement
Rising
High
(1)
(2)
(3)
High
Falling
Decrement
Low
Falling
HITACHI 273
Low
Rising
Time