upd78f0114hgb-8es-a Renesas Electronics Corporation., upd78f0114hgb-8es-a Datasheet - Page 96

• Manufacturer Part Number: upd78f0114hgb-8es-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

5.1 Functions of Clock Generator
5.2 Configuration of Clock Generator
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The clock generator generates the clock to be supplied to the CPU and peripheral hardware.
The following three system clock oscillators are available.
The clock generator includes the following hardware.
Control registers
Oscillators
High-speed system clock oscillator
The following two high-speed system clock oscillators are available.
High-speed system clock oscillation can be selected using the option byte. Refer to CHAPTER 22 OPTION
BYTE for details.
The high-speed system clock oscillator can be stopped by executing the STOP instruction or setting the main
OSC control register (MOC) and processor clock control register (PCC).
Internal oscillator
The Internal oscillator oscillates a clock of f
internal oscillation mode register (RCM) when “can be stopped by software” is set by the option byte and the
high-speed system clock is used as the CPU clock.
Subsystem clock oscillator
The subsystem clock oscillator oscillates a clock of f
subsystem clock oscillator is not used, setting not to use the on-chip feedback resistor is possible using the
processor clock control register (PCC), and the operating current can be reduced in the STOP mode.
Remarks 1. f
Crystal/ceramic oscillator: Oscillates a clock of f
External RC oscillator: Oscillates a clock of f
Item
2. f
3. f
XP
R
XT
:
: High-speed system clock oscillation frequency
: Subsystem clock oscillation frequency
Internal oscillation clock oscillation frequency
Processor clock control register (PCC)
Internal oscillation mode register (RCM)
Main clock mode register (MCM)
Main OSC control register (MOC)
Oscillation stabilization time counter status register (OSTC)
Oscillation stabilization time select register (OSTS)
High-speed system clock oscillator
Internal oscillator
Subsystem clock oscillator
Table 5-1. Configuration of Clock Generator
CHAPTER 5 CLOCK GENERATOR
User’s Manual U16961EJ4V0UD
R
XP
= 240 kHz (TYP.). Oscillation can be stopped by setting the
= 3 to 4 MHz
XP
= 2 to 16 MHz
XT
= 32.768 kHz. Oscillation cannot be stopped. When
Configuration