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CHAPTER 4 CLOCK GENERATOR
User’s Manual U12697EJ3V0UM
Example
MOV STBC #byte
NOP
NOP
NOP
•
•
•
3. When CK2 = 0, the oscillation of the main system clock does not stop even if MCK is set
to 1 (Refer to 4.5.1 Main system clock operations).
Remarks 1.
f
XX
: Main system clock frequency (f
X
or f
X
/2)
f
X
: Main system clock oscillation frequency
f
XT
: Subsystem clock oscillation frequency
2.
×
: don’t care
(2) Oscillation mode selection register (CC)
This register specifies whether clock output from the main system clock oscillator with the same frequency as
the external clock, or clock output that is half of the original frequency is used to operate the internal circuit.
CC is set by a 1-bit or 8-bit memory manipulation instruction.
RESET input sets CC to 00H.
Figure 4-3. Format of Oscillation Mode Selection Register (CC)
Address: 0FF7AH After reset: 00H R/W
Symbol
7
6
5
4
3
2
1
0
CC
ENMP
0
0
0
0
0
0
0
ENMP
Main system clock selection
0
Half of original oscillation frequency
1
Through rate clock mode
Cautions
1. If the subsystem clock is selected via the standby control mode register (STBC), the
ENMP bit specification becomes invalid.
2. The ENMP bit cannot be reset by software. This bit is reset performing the system reset.
Содержание mPD784225 Series
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