r4f2426 Renesas Electronics Corporation., r4f2426 Datasheet - Page 1119

• Manufacturer Part Number: r4f2426
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

This LSI has an on-chip clock pulse generator (CPG) that generates the system clock (
internal clocks. The clock pulse generator consists of an oscillator circuit, a system-clock PLL
circuit and a divider.
Figure 23.1 shows a block diagram of the clock pulse generator.
The frequency of the system clock from the oscillator can be changed by means of the system-
clock PLL circuit and divider. Frequency changes are made by software by means of settings in
the PLL control register (PLLCR).
Legend:
PLLCR: PLL control register
EXTAL
XTAL
Oscillator
Figure 23.1 Block Diagram of Clock Pulse Generator
Section 23 Clock Pulse Generator
System-clock
PLL circuit
(×1, 2)
STC0, STC1
PLLCR
Divider
Rev. 1.00 Sep. 19, 2008 Page 1091 of 1270
System clock
to φ pin
Section 23 Clock Pulse Generator
REJ09B0466-0100
Internal clock
to peripheral
modules
φ
) and