External Clock Input - Renesas H8S/2319 series Hardware Manual

18.3.2

External Clock Input

Circuit Configuration: An external clock signal can be input as shown in the examples in figure
18-5. If the XTAL pin is left open, make sure that stray capacitance is no more than 10 pF.
In example (b), make sure that the external clock is held high in standby mode.
EXTAL
XTAL
EXTAL
XTAL
External Clock: The external clock signal should have the same frequency as the system clock
(φ).
Table 18-4 and figure 18-6 show the input conditions for the external clock.
Rev. 5.00, 12/03page 774 of 1088
(a) XTAL pin left open
(b) Complementary clock input at XTAL pin
Figure 18-5 External Clock Input (Examples)
External clock input
Open
External clock input