HD64F2638F20J Datasheet, PDF (959/1512 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
Section 22A Clock Pulse Generator
(H8S/2636 Group, H8S/2638 Group, H8S/2630 Group)
22A.3.2 External Clock Input
Circuit Configuration
An external clock signal can be input as shown in the examples in figure 22A-6. 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.
In this case, the input clock frequency should be between 4 MHz and 20 MHz.
EXTAL
XTAL
Open
External clock input
(a) XTAL pin left open
EXTAL
XTAL
External clock input
(b) Complementary clock input at XTAL pin
Figure 22A-6 External Clock Input (Examples)
REJ09B0103-0800 Rev. 8.00
May 28, 2010
Page 909 of 1458