HD6417034B RENESAS [Renesas Technology Corp], HD6417034B Datasheet - Page 126

• Manufacturer Part Number: HD6417034B
• Description: 32-Bit RISC Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 7 Clock Pulse Generator (CPG)
7.3
Board Design: When designing the board, place the crystal resonator and its load capacitors as
close as possible to the XTAL and EXTAL pins. Route no other signal lines near the XTAL and
EXTAL pin signal lines to prevent induction from interfering with correct oscillation. See figure
7.6.
Duty Cycle Correction Circuit: Duty cycle corrections are conducted for an input clock over 5
MHz. Duty cycles may not be corrected for a clock of under 5 MHz, but AC characteristics for the
high-level pulse width (t
will operate normally. Figure 7.7 shows the standard characteristics of duty cycle correction. This
duty cycle correction circuit is not for correcting transient fluctuations and jitter in the input clock.
Thus, it takes several tens of microseconds to obtain a stable clock after duty cycle correction is
performed.
Rev. 7.00 Jan 31, 2006 page 100 of 658
REJ09B0272-0700
Usage Notes
Figure 7.6 Precaution on Oscillator Circuit Board Design
CH
) and low-level pulse width (t
C
C
L1
L2
No crossing
signal lines
CL
) of the clock are satisfied, and the chip
XTAL
EXTAL