Datasheet

Section 11 16-Bit Timer Pulse Unit (TPU)
Page 786 of 1408 R01UH0309EJ0500 Rev. 5.00
Sep 24, 2012
H8S/2456, H8S/2456R, H8S/2454 Group
11.10 Usage Notes
11.10.1 Module Stop Function Setting
TPU operation can be disabled or enabled using the module stop control register. The initial
setting is for TPU operation to be halted. Register access is enabled by clearing the module stop
state. For details, refer to section 24, Power-Down Modes.
11.10.2 Input Clock Restrictions
The input clock pulse width must be at least 1.5 states in the case of single-edge detection, and at
least 2.5 states in the case of both-edge detection. The TPU will not operate properly with a
narrower pulse width.
In phase counting mode, the phase difference and overlap between the two input clocks must be at
least 1.5 states, and the pulse width must be at least 2.5 states. Figure 11.45 shows the input clock
conditions in phase counting mode.
Overlap
Phase
diffe-
rence
Phase
diffe-
rence
Overlap
TCLKA
(TCLKC)
TCLKB
(TCLKD)
Pulse width Pulse width
Pulse width Pulse width
Notes: Phase difference and overlap
Pulse width
: 1.5 states or more
: 2.5 states or more
Figure 11.45 Phase Difference, Overlap, and Pulse Width in Phase Counting Mode