SH7280 Datasheet, PDF (119/1726 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine family

Table 4.6 Crystal Resonator Characteristics
Frequency (MHz)
10
R_s max. (Ω) (reference value) 60
C₀ max. (pF) (reference value) 7
Section 4 Clock Pulse Generator (CPG)
12.5
50
7
4.6.2 External Clock Input Method
Figure 4.4 shows an example of an external clock input connection. Drive the external clock high
when it is stopped in software standby mode. During operation, input an external clock with a
frequency of 10 to 12.5 MHz. Make sure the parasitic capacitance of the XTAL pin is 10 pF or
less.
Even when inputting an external clock, be sure to wait at least for the oscillation settling time in
power-on sequence or in canceling software standby mode, in order to ensure the PLL settling
time.
EXTAL
XTAL
External clock input
Open state
Figure 4.4 Example of External Clock Connection
Rev. 1.00 Jun. 26, 2008 Page 89 of 1692
REJ09B0393-0100