M16C26 Datasheet, PDF (35/239 Pages) Renesas Technology Corp – 16-BIT CMOS SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/20 SERIES

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Preliminary Specifications Rev. 0.9
Specifications in this manual are tentative
Clock Generating Circuit
and
subject to change.
SINGLE-CHIP 16-BIT
M16C/26 Group
CMOS MICROCOMPUTER
Figure 1.8.1 shows some examples of the main clock circuit, one using an oscillator connected to the
circuit, and the other one using an externally derived clock for input. Figure 1.8.2 shows some examples of
sub-clock circuits, one using an oscillator connected to the circuit, and the other one using an externally
derived clock for input. Circuit constants in Figures 1.8.1 and 1.8.2 vary with each oscillator used. Use the
values recommended by the manufacturer of your oscillator.
Microcomputer
(Built-in feedback resistor)
XIN
XOUT
(Note)
Rd
CIN
COUT
Microcomputer
(Built-in feedback resistor)
XIN
XOUT
Open
Externally derived clock
Vcc
Vss
Note: Insert a damping resistor if required. The resistance will vary depending on the oscillator and the oscillation drive
capacity setting. Use the value recommended by the maker of the oscillator.
When the oscillation drive capacity is set to low, check that oscillation is stable. Also, if the oscillator manufacturer's
data sheet specifies that a feedback resistor be added external to the chip, insert a feedback resistor between XIN
and XOUT following the instruction.
Figure 1.8.1. Examples of main clock
Microcomputer
(Built-in feedback resistor)
XCIN
XCOUT
(Note)
RCd
CCIN
CCOUT
Microcomputer
(Built-in feedback resistor)
XCIN
XCOUT
Open
Externally derived clock
Vcc
Vss
Note: Insert a damping resistor if required. The resistance will vary depending on the oscillator and the oscillation drive
capacity setting. Use the value recommended by the maker of the oscillator.
Also, if the oscillator manufacturer's data sheet specifies that a feedback resistor be added external to the chip,
insert a feedback resistor between XCIN and XCOUT following the instruction.
Figure 1.8.2. Examples of sub-clock
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