
User’s Manual U14826EJ5V0UD
69
CHAPTER 7 CLOCK GENERATOR (
µ
PD789860 SUBSERIES)
7.1 Clock Generator Functions
The clock generator generates the clock to be supplied to the CPU and peripheral hardware.
The following type of system clock oscillator is used.
•
System clock (crystal/ceramic) oscillator
This circuit oscillates at 1.0 to 5.0 MHz. Oscillation can be stopped by executing the STOP instruction.
7.2 Clock Generator Configuration
The clock generator includes the following hardware.
Table 7-1. Configuration of Clock Generator
Item Configuration
Control register
Processor clock control register (PCC)
Oscillator Crystal/ceramic
oscillator
Figure 7-1. Block Diagram of Clock Generator
Prescaler
System clock
oscillator
f
X
Prescaler
Standby
controller
Wait
controller
CPU clock (f
CPU
)
STOP
f
X
2
2
Clock to peripheral
hardware
PCC0
Internal bus
Processor clock control
register (PCC)
X1
X2
Selector
Содержание PD789860
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