upd78f0148m1gka1-9eu Renesas Electronics Corporation., upd78f0148m1gka1-9eu Datasheet - Page 140

• Manufacturer Part Number: upd78f0148m1gka1-9eu
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

140
Caution When using the X1 oscillator and subsystem clock oscillator, wire as follows in the area
Figure 6-10 shows examples of incorrect resonator connection.
Remark When using the subsystem clock, replace X1 and X2 with XT1 and XT2, respectively. Also, insert
enclosed by the broken lines in Figures 6-8 and 6-9 to avoid an adverse effect from wiring
capacitance.
• Keep the wiring length as short as possible.
• Do not cross the wiring with the other signal lines.
• Do not route the wiring near a signal line through which a high fluctuating current flows.
• Always make the ground point of the oscillator capacitor the same potential as V
• Do not fetch signals from the oscillator.
Note that the subsystem clock oscillator is designed as a low-amplitude circuit for reducing
power consumption.
resistors in series on the XT2 side.
ground the capacitor to a ground pattern through which a high current flows.
(a) Too long wiring
V
Figure 6-10. Examples of Incorrect Resonator Connection (1/2)
SS
X1
CHAPTER 6 CLOCK GENERATOR
X2
User’s Manual U15947EJ3V1UD
V
SS
(b) Crossed signal line
X1
PORT
X2
SS
. Do not