Section 26 Clock Pulse Generator
Rev. 3.00 Jan 25, 2006 page 762 of 872
REJ09B0286-0300
The subclock input is controlled by software according to the EXCLE bit setting in the low power
control register. For details on the low power control register, see section 27.1.2, Low-Power
Control Register (LPWRCR).
26.1
Oscillator
Clock pulses can be supplied either by connecting a crystal resonator or by providing external
clock input.
26.1.1
Connecting a Crystal Oscillator
Figure 26.2 shows a typical method of connecting a crystal resonator. An appropriate damping
resistance R
d
, given in table 26.1, should be used. An AT-cut parallel-resonance crystal resonator
should be used.
Figure 26.3 shows the equivalent circuit of a crystal resonator. A crystal resonator having the
characteristics given in table 26.2 should be used.
A crystal resonator with frequency identical to that of the system clock (
φ
) should be used.
EXTAL
XTAL
R
d
C
L2
C
L1
C
L1
= C
L2
= 10 to 22 pF
Figure 26.2 Typical Connection to Crystal Resonator
Table 26.1 Damping Resistance Values
Frequency (MHz)
5
8
10
12
16
20
25
R
d
(
Ω
Ω
Ω
Ω
)
300
200
0
0
0
0
0
XTAL
C
L
AT-cut parallel-resonance crystal resonator
EXTAL
C
0
L
R
s
Figure 26.3 Equivalent Circuit of Crystal Resonator
Содержание H8S/2158
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Страница 36: ...Rev 3 00 Jan 25 2006 page xxxiv of lii B Product Lineup 863 C Package Dimensions 864 Index 865...
Страница 47: ...Rev 3 00 Jan 25 2006 page xlv of lii Appendix Figure C 1 Package Dimensions TBP 112A 864...
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Страница 70: ...Section 1 Overview Rev 3 00 Jan 25 2006 page 16 of 872 REJ09B0286 0300...
Страница 118: ...Section 3 MCU Operating Modes Rev 3 00 Jan 25 2006 page 64 of 872 REJ09B0286 0300...
Страница 126: ...Section 4 Exception Handling Rev 3 00 Jan 25 2006 page 72 of 872 REJ09B0286 0300...
Страница 198: ...Section 6 Bus Controller Rev 3 00 Jan 25 2006 page 144 of 872 REJ09B0286 0300...
Страница 326: ...Section 10 8 Bit PWM Timer PWM Rev 3 00 Jan 25 2006 page 272 of 872 REJ09B0286 0300...
Страница 440: ...Section 15 Watchdog Timer WDT Rev 3 00 Jan 25 2006 page 386 of 872 REJ09B0286 0300...
Страница 606: ...Section 17 I 2 C Bus Interface IIC Rev 3 00 Jan 25 2006 page 552 of 872 REJ09B0286 0300...
Страница 742: ...Section 19 Multimedia Card Interface MCIF Rev 3 00 Jan 25 2006 page 688 of 872 REJ09B0286 0300...
Страница 744: ...Section 20 Encryption Operation Circuit DES and GF Rev 3 00 Jan 25 2006 page 690 of 872 REJ09B0286 0300...
Страница 750: ...Section 21 D A Converter Rev 3 00 Jan 25 2006 page 696 of 872 REJ09B0286 0300...
Страница 768: ...Section 22 A D Converter Rev 3 00 Jan 25 2006 page 714 of 872 REJ09B0286 0300...
Страница 770: ...Section 23 RAM Rev 3 00 Jan 25 2006 page 716 of 872 REJ09B0286 0300...
Страница 824: ...Section 26 Clock Pulse Generator Rev 3 00 Jan 25 2006 page 770 of 872 REJ09B0286 0300...
Страница 844: ...Section 27 Power Down Modes Rev 3 00 Jan 25 2006 page 790 of 872 REJ09B0286 0300...
Страница 878: ...Section 28 List of Registers Rev 3 00 Jan 25 2006 page 824 of 872 REJ09B0286 0300...
Страница 926: ...Index Rev 3 00 Jan 25 2006 page 872 of 872 REJ09B0286 0300...