Renesas rl78 User Manual

Page of 1004
 
RL78/G1A 
 
CHAPTER  5   CLOCK  GENERATOR 
R01UH0305EJ0200  Rev.2.00 
 
 
160  
Jul 04, 2013 
Figure 5-13 shows examples of incorrect resonator connection. 
 
Figure 5-13.  Examples of Incorrect Resonator Connection (1/2) 
 
 
(a)  Too long wiring  
(b) Crossed signal line 
 
X2
V
SS
X1
X1
NG
NG
NG
V
SS
X2
PORT
 
 
 
(c)  The X1 and X2 signal line wires cross.  
(d) A power supply/GND pattern exists  
 
 
under the X1 and X2 wires. 
 
X2
V
SS
X1
X1
Power supply/GND pattern
V
SS
X2
Note
 
 
Note  Do not place a power supply/GND pattern under the wiring section (section indicated by a broken line in the 
figure) of the X1 and X2 pins and the resonators in a multi-layer board or double-sided board. 
Do not configure a layout that will cause capacitance elements and affect the oscillation characteristics. 
 
Remark   When using the subsystem clock, replace X1 and X2 with XT1 and XT2, respectively.  Also, insert resistors 
in series on the XT2 side.