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HD6433832S Datasheet, PDF (100/560 Pages) Renesas Technology Corp – single-chip microcomputers | |||
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Section 4 Clock Pulse Generators
4.1 Overview
Clock oscillator circuitry (CPG: clock pulse generator) is provided on-chip, including both a
system clock pulse generator and a subclock pulse generator. The system clock pulse generator
consists of a system clock oscillator and system clock dividers. The subclock pulse generator
consists of a subclock oscillator circuit and a subclock divider.
4.1.1 Block Diagram
Figure 4.1 shows a block diagram of the clock pulse generators.
OSC 1
OSC 2
X1
X2
Ï OSC
System clock
System clock
oscillator
divider (1/2)
(fOSC)
ÏOSC /2
System clock Ï OSC/16
divider (1/8)
System clock pulse generator
Subclock
oscillator
ÏW
(f W )
Subclock
divider
(1/2, 1/4, 1/8)
Ï W/2
Ï W/4
Ï W/8
Ï
Prescaler S
(13 bits)
Ï SUB
Subclock pulse generator
Prescaler W
(5 bits)
Figure 4.1 Block Diagram of Clock Pulse Generators
Ï /2
to
Ï /8192
ÏW
Ï W/2
Ï W/4
Ï W/8
to
Ï W/128
4.1.2 System Clock and Subclock
The basic clock signals that drive the CPU and on-chip peripheral modules are Ï and ÏSUB. Four of
the clock signals have names: Ï is the system clock, ÏSUB is the subclock, ÏOSC is the oscillator
clock, and ÏW is the watch clock.
The clock signals available for use by peripheral modules are Ï/2, Ï/4, Ï/8, Ï/16, Ï/32, Ï/64,
Ï/128, Ï/256, Ï/512, Ï/1024, Ï/2048, Ï/4096, Ï/8192, ÏW, ÏW/2, ÏW/4, ÏW/8, ÏW/16, ÏW/32, ÏW/64,
and ÏW/128. The clock requirements differ from one module to another.
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