SH7144_08 Datasheet, PDF (100/930 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family/SH7144 Series

4. Clock Pulse Generator
Table 4.3 Crystal Resonator Characteristics
Frequency (MHz)
4
8
10
12.5
Rs max (Ω)
120
80
60
50
C0 max (pF)
7
7
7
7
4.1.2 External Clock Input Method
Figure 4.4 shows an example of an external clock input connection. In this case, make the external
clock high level to stop it when in software standby mode. During operation, make the external
input clock frequency 4 to 12.5 MHz.
When leaving the XTAL pin open, make sure the parasitic capacitance is less than 10 pF.
Even when inputting an external clock, be sure to wait at least the oscillation stabilization time in
power-on sequence or in releasing software standby mode, in order to ensure the PLL stabilization
time.
EXTAL
XTAL
External clock input
Open state
Figure 4.4 Example of External Clock Connection
Rev.4.00 Mar. 27, 2008 Page 56 of 882
REJ09B0108-0400