Datasheet

Table Of Contents
Section 21 Clock Pulse Generator
REJ09B0140-0900 Rev. 9.00 Page 675 of 846
Sep 16, 2010
H8S/2215 Group
21.6 USB Operating Clock (48 MHz)
USB operating clock can be supplied by connecting a ceramic resonator, or by input of an external
clock.
21.6.1 Connecting a Ceramic Resonator
Circuit Configuration: A crystal resonator can be connected as shown in the example in figure
21.7.
EXTAL48
XTAL48
R
d
R
f
Ceramic resonator: CSTCW48M0X11∗∗∗-R0
(Murata Manufacturing Co.,Ltd.)
Ceramic
Resonator
*** represents three-digit alphanumerics which express "Individual Specification".
Since the frequency for USB requires high accuracy, the official product type name will be defined
after the performance of the user's board on which the resonator is mounted is evaluated and its
frequency is adjusted.
Please contact your Renesas Electronics sales agency.
Ta = 0 to 70 °C
Contact your Renesas Electronics sales agency for details of Rf and Rd values.
Note:
Figure 21.7 Connection of Ceramic Resonator
21.6.2 Inputting an 48-MHz External Clock
An external clock signal can be input as shown in an example in figure 21.8. The XTAL48 pin
must be left open.
EXTAL48
XTAL48
External clock input
Open state
Figure 21.8 Connection of Ceramic Resonator