p2125vps20 Renesas Electronics Corporation., p2125vps20 Datasheet - Page 593

• Manufacturer Part Number: p2125vps20
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Table 21.2 Crystal Resonator Parameters
21.1.2
Figure 21.4 shows a typical method of inputting an external clock signal. To leave the XTAL pin
open, incidental capacitance should be 10 pF or less. To input an inverted clock to the XTAL pin,
the external clock should be set to high in standby mode, subactive mode, subsleep mode, and
watch mode. External clock input conditions are shown in table 21.3. The frequency of the
external clock should be the same as that of the system clock (φ).
Frequency (MHz)
R
C
S
0
(max.) (pF)
(max.) (Ω)
External Clock Input Method
EXTAL
XTAL
EXTAL
XTAL
(a) Example of external clock input when XTAL pin is left open
(b) Example of external clock input when an inverted clock is input to XTAL pin
Figure 21.4 Example of External Clock Input
8
80
10
70
Open
12
60
External clock input
External clock input
7
Rev. 1.00 Sep. 21, 2006 Page 555 of 658
Section 21 Clock Pulse Generator
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REJ09B0310-0100
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