H8S2245 datasheet(589/818 Pages) RENESAS

Part #	H8S2245

Description	Renesas 16-Bit Single-Chip Microcomputer H8S Family / H8S/2200 Series

PDF	818 Pages

Scroll/Zoom	100%

Manufacturer	RENESAS [Renesas Technology Corp]

Direct Link	http://www.renesas.com

Logo

589 / 818 page

Section 17 Clock Pulse Generator

Rev.3.00 Mar. 26, 2007 Page 547 of 772

REJ09B0355-0300

Crystal resonator

Figure 17.3 shows the equivalent circuit of the crystal resonator. Use a crystal resonator that has

the characteristics shown in table 17.3 and the same resonance frequency as the system clock (

φ).

XTAL

AT-cut parallel-resonance type

EXTAL

LRs

Figure 17.3 Crystal Resonator Equivalent Circuit

Table 17.3

Crystal Resonator Parameters

Frequency (MHz)

24812

s max (Ω

Ω

Ω)

500

120

0 max (pF)

777777

Note on Board Design

When a crystal resonator is connected, the following points should be noted:

Other signal lines should be routed away from the oscillator circuit to prevent induction from

interfering with correct oscillation. See figure 17.4.

When designing the board, place the crystal resonator and its load capacitors as close as possible

to the XTAL and EXTAL pins.

CL2

Signal A Signal B

CL1

H8S/2245

XTAL

EXTAL

Avoid

Figure 17.4 Example of Incorrect Board Design

H8S2245 Datasheet(PDF) 589 Page - Renesas Technology Corp