MC-78F0712-KIT Renesas Electronics America, MC-78F0712-KIT Datasheet - Page 74

• Manufacturer Part Number: MC-78F0712-KIT
• Description: KIT REF SYSTEM 78K0 UPD78F0712
• Manufacturer: Renesas Electronics America

Specifications of MC-78F0712-KIT

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

5.1
72
The clock generator generates the clock to be supplied to the CPU and peripheral hardware.
The following kind of system clock and clock oscillator are selectable.
(1) High-speed system clock
(2) Internal low-speed oscillation clock
Remarks 1. f
Functions of Clock Generator
The X1 clock or the internal high-speed oscillation clock can be selected as the high-speed system clock by
using the option byte.
The operation of the oscillator stops when the oscillator is not selected by using the option byte.
<1> X1 oscillator
<2> Internal high-speed oscillator
Internal low-speed oscillator
This circuit oscillates a clock of f
main system clock (5 to 20 MHz) can also be supplied from the X1 and X2 pin. Oscillation can be
stopped by executing the STOP instruction or setting the main OSC control register (MOC).
The internal high-speed oscillator oscillates a clock of f
executing the STOP instruction or setting the main OSC control register (MOC).
The internal low-speed oscillator oscillates a clock of f
internal low-speed oscillation clock always starts operating.
Oscillation can be stopped by setting the internal oscillation mode register (RCM) when “internal low-
speed oscillator can be stopped by software” is set by the option byte.
The internal low-speed oscillation clock can be used as the CPU clock. The following hardware operates
with the internal low-speed oscillation clock.
CPU (when internal low-speed oscillation clock is selected)
Watchdog timer (when internal low-speed oscillation clock is selected)
8-bit timer 51 (when f
2. f
3. f
X
RH
RL
:
:
:
X1 clock oscillation frequency
Internal high-speed oscillation clock frequency
Internal low-speed oscillation clock frequency
RL
/2
CHAPTER 5 CLOCK GENERATOR
7
is selected)
User’s Manual U17890EJ2V0UD
X
= 5 to 20 MHz by connecting a resonator to X1 and X2. An external
RH
RL
= 8 MHz (TYP.). Oscillation can be stopped by
= 240 kHz (TYP.). After a reset release, the