SH7147 Datasheet, PDF (96/1108 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperH™ RISC engine Family

Section 4 Clock Pulse Generator (CPG)
Table 4.7 Crystal Resonator Characteristics
Frequency (MHz)
8
10
Rs Max. (Ω) (Reference values) 80
60
C0 Max. (pF) (Reference values) 7
7
4.6.2 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 8 to 10 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. 3.00 Oct. 06, 2008 Page 72 of 1080
REJ09B0230-0300