RX610 Group
7. Clock Generation Circuit
R01UH0032EJ0120 Rev.1.20
Page 168 of 1006
Feb 20, 2013
7.7.2
Notes on Resonator
Since various resonator characteristics relate closely to the user's board design, adequate evaluation is required on the
user side before use, referencing the resonator connection example shown in this section. The circuit constants for the
resonator depend on the resonator to be used and the stray capacitance of the mounting circuit. Therefore, the circuit
constants should be determined in full consultation with the resonator manufacturer. The voltage to be applied between
the resonator pins must be within the absolute maximum rating.
7.7.3
Notes on Board Design
When using a crystal resonator, place the resonator and its capacitors as close to the XTAL and EXTAL pins as possible.
Other signal lines should be routed away from the oscillation circuit as shown in figure 7.5 to prevent induction from
interfering with correct oscillation.
The XTAL pin and the reset pin are crossly arranged on the RX610 Group. Therefore, to avoid the reference from the
clock signal, the reset signal should be guarded by GND.
EXTAL
XTAL
C
L2
C
L1
This LSI
Prohibited
Signal A
Signal B
Figure 7.5 Notes on Board Design for Oscillation Circuit
Figure 7.6 shows a recommended external circuit for the PLL circuit. Separate pins PLLVcc, PLLVss, Vcc, and Vss from
the board power supply source, and be sure to insert bypass capacitors CPB and CB close to the pins.
Note:
*
CB, CPB: Multilayer ceramic capacitor
Rp: 100
Ω
CPB: 0.1
µ
F
*
CB: 0.1
µ
F
*
PLLVcc
Vcc
PLLVss
Vss
Figure 7.6 Recommended External Circuit for PLL Circuit
Summary of Contents for RX600 Series
Page 1006: ...RX610 Group R01UH0032EJ0120 ...