NEC PD78078 用户手册
166
CHAPTER 7 CLOCK GENERATOR
Subsystem
Clock
Oscillator
Clock
Oscillator
Main
System
Clock
Oscillator
System
Clock
Oscillator
X2
X1
XT2
XT1/P07
FRC
STOP
MCC
FRC
CLS CSS PCC2 PCC1
Internal Bus
Standby
Control
Circuit
Control
Circuit
To INTP0
Sampling Clock
Sampling Clock
2
f
XX
2
2
f
XX
2
3
f
XX
2
4
f
XX
Prescaler
Clock to
Peripheral
Hardware
Peripheral
Hardware
Prescaler
Oscillation Mode
Selection Register
Watch Timer,
Clock Output
Function
Clock Output
Function
f
XX
CPU Clock
(f
(f
CPU
)
Wait
Control
Circuit
Control
Circuit
Divider
Selector
f
X
f
XT
2
f
X
MCS
Processor Clock
Control Register
Control Register
1/2
2
f
XT
PCC0
3
Selector
7.2 Clock Generator Configuration
The clock generator consists of the following hardware.
Table 7-1. Clock Generator Configuration
Item
Configuration
Control register
Processor clock control register (PCC)
Oscillation mode selection register (OSMS)
Oscillator
Main system clock oscillator
Subsystem clock oscillator
Figure 7-1. Block Diagram of Clock Generator