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NEC PD78F9488 User Manual

Page 97

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CHAPTER 5 CLOCK GENERATOR

User’s Manual U15331EJ4V1UD

97

Figure 5-2. Clock Generator Block Diagram (

µPD78F9488, 78F9489)

Subsystem

clock oscillator

f

XT

X1

X2

XT1

XT2

Main system

clock oscillator

f

X

f

X

2

2

f

XTT

2

1/2

Prescaler

Clock to peripheral
hardware

Timer 50
Watch timer
LCD controller/driver

CPU clock
(f

CPU

)

Standby

controller

Wait

controller

Selector

STOP

MCC PCC1

CLS CSS0

Internal bus

Subclock oscillation
mode register (SCKM)

FRC SCC

Internal bus

Subclock control
register (CSS)

Processor clock
control register (PCC)

×

4 multiplication

circuit

×

2 multiplication

circuit

Selector

Subclock selection
register (SSCK)

SCT

f

XTT

8f

XT


Remark
f

XTT

: f

XT

or 8f

XT

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