HD6475328CG Datasheet, PDF (152/459 Pages) Hitachi Semiconductor – Manual Gives a Hardware Description

Section 8 Clock Pulse Generator
8.1 Overview
The H8/532 chip has a built-in clock pulse generator (CPG) consisting of an oscillator circuit, a
system (ø) clock divider, an E clock divider, and a group of prescalers. The prescalers generate
clock signals for the on-chip supporting modules.
8.1.1 Block Diagram
XTAL
EXTAL
Oscillator
circuit
Divider
÷2
Divider
÷8
CPG
Prescaler
ø
E
ø/2 to ø/4096
Figure 8-1 Block Diagram of Clock Pulse Generator
8.2 Oscillator Circuit
If an external crystal is connected across the EXTAL and XTAL pins, the on-chip oscillator circuit
generates a clock signal for the system clock divider. Alternatively, an external clock signal can
be applied to the EXTAL pin.
Connecting an External Crystal
(1) Circuit Configuration: An external crystal can be connected as in the example in figure 8-2.
An AT-cut parallel resonating crystal should be used.
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