UPD78F1502AGK-GAK-AX Datasheet, PDF (240/1031 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcontrollers

78K0R/Lx3
CHAPTER 5 CLOCK GENERATOR
Figure 5-12. Examples of Incorrect Resonator Connection (1/2)
(a) Too long wiring
(b) Crossed signal line
PORT
VSS
X1
X2
VSS
X1
X2
NG
NG
NG
(c) Signal lines of X1 and X2 cross
(d) Power supply/GND pattern exists underneath X1 and X2
wiring
VSS
X1
X2
VSS X1
X2
Note
Power supply/GND pattern
Note Do not place a power supply/GND pattern underneath the wiring section (in broken lines above) of the X1 and
X2 pins and resonator in the multilayer board and double-sided board.
Do not configure a layout that may 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.
R01UH0004EJ0501 Rev.5.01
224
Jun 20, 2011