SH7052 Datasheet, PDF (85/919 Pages) Renesas Technology Corp – SuperHTM RISC engine

Open
XTAL
External clock input
EXTAL
Figure 4.5 External Clock Input Method (Example)
4.4 Usage Notes
Notes on Board Design: When connecting a crystal oscillator, observe the following precautions:
• To prevent induction from interfering with correct oscillation, do not route any signal lines
near the oscillator circuitry (figure 4.6).
• When designing the board, place the crystal oscillator and its load capacitors as close as
possible to the XTAL and EXTAL pins.
Figure 4.6 shows the precautions regarding oscillator circuit system board design.
Crossing of signal
lines prohibited
CL1
XTAL
CL2
EXTAL
Figure 4.6 Precautions for Oscillator Circuit System Board Design
PLL Oscillation Power Supply: Place oscillation capacitor C1 and resistor R1 close to the PLL
CAP pin, and ensure that no other signal lines cross this line. Supply the C1 ground from PLLV_SS.
Separate PLLV_CC and PLLV_SS from the other V_CC and V_SS lines at the board power supply source,
and be sure to insert bypass capacitors C_PB and C_B close to the pins.
59