h8s-2138 Renesas Electronics Corporation., h8s-2138 Datasheet - Page 723

• Manufacturer Part Number: h8s-2138
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

23.1
The H8S/2138 Group and H8S/2134 Group have an on-chip clock pulse generator (CPG) that
generates the system clock ( ), the bus master clock, and internal clocks.
The clock pulse generator consists of an oscillator circuit, a duty adjustment circuit, clock
selection circuit, medium-speed clock divider, bus master clock selection circuit, subclock input
circuit, and waveform shaping circuit.
23.1.1
Figure 23.1 shows a block diagram of the clock pulse generator.
EXTAL
XTAL
EXCL
Overview
Block Diagram
input circuit
Oscillator
Subclock
Figure 23.1 Block Diagram of Clock Pulse Generator
Section 23 Clock Pulse Generator
adjustment
Waveform
shaping
circuit
circuit
Duty
WDT1 count clock
SUB
selection
circuit
Clock
System clock
To
pin
Rev. 4.00 Jun 06, 2006 page 669 of 1004
Medium-speed
clock divider
Section 23 Clock Pulse Generator
Internal clock
To supporting
modules
/2 to /32
Bus master
selection
REJ09B0301-0400
circuit
clock
Bus master clock
To CPU, DTC