HD64F2638F20J Datasheet, PDF (971/1512 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 22B Clock Pulse Generator
(H8S/2639 Group, H8S/2635 Group)
22B.3.2 External Clock Input
Circuit Configuration
An external clock signal can be input as shown in the examples in figure 22B-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 5 MHz.
EXTAL
XTAL
Open
External clock input
(a) XTAL pin left open
EXTAL
External clock input
XTAL
(b) Complementary clock input at XTAL pin^*
Note: * In the case of the H8S/2635 Group, do not input a complementary clock to the XTAL pin.
Figure 22B-6 External Clock Input (Examples)
REJ09B0103-0800 Rev. 8.00
May 28, 2010
Page 921 of 1458