CHAPTER 5 CLOCK GENERATOR
User’s Manual U15075EJ2V1UD
106
(2) Suboscillation
mode register (SCKM)
SCKM selects a feedback resistor for the subsystem clock, and controls the oscillation of the clock.
SCKM is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets SCKM to 00H.
Figure 5-3. Format of Suboscillation Mode Register
Feedback resistor selection
Note
0
0
0
0
0
0
FRC
SCC
SCKM
Symbol
Address
After reset
R/W
FFF0H
00H
R/W
7
6
5
4
3
2
1
0
FRC
0
1
On-chip feedback resistor used
On-chip feedback resistor not used
Control of subsystem clock oscillator operation
SCC
0
1
Operation enabled
Operation disabled
Note
The feedback resistor is necessary to adjust the bias point of the oscillation waveform to close to the mid
point of the supply voltage. Only when the subclock is not used, the power consumption in STOP mode can
be further reduced by setting FRC = 1.
Caution Bits 2 to 7 must be set to 0.