SH7052 Datasheet, PDF (84/919 Pages) Renesas Technology Corp – SuperHTM RISC engine

Table 4.3 Damping Resistance Values (Recommended Values)
Parameter
Rd (Ω)
Frequency (MHz)
5
10
500
0
Crystal Oscillator: Figure 4.4 shows an equivalent circuit of the crystal oscillator. Use a crystal
oscillator with the characteristics listed in table 4.4.
EXTAL
L
CL
Rs
C0
XTAL
Figure 4.4 Crystal Oscillator Equivalent Circuit
Table 4.4 Crystal Oscillator Parameters (Recommended Values)
Frequency (MHz)
Parameter
5
10
Rs max (Ω)
100
50
C0 max (pF)
7
7
The crystal oscillator manufacturer should be consulted concerning the compatibility between the
crystal oscillator and the chip.
4.3.2 External Clock Input Method
An example of external clock input connection is shown in figure 4.5.
When the XTAL pin is placed in the open state, the parasitic capacitance should be 10 pF or less.
Even when an external clock is input, provide for a wait of at least the oscillation settling time
when powering on or exiting standby mode in order to secure the PLL settling time.
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