![](http://datasheet.mmic.net.cn/30000/M30956FKTGP_datasheet_2359453/M30956FKTGP_104.png)
8. Clock Generation Circuits
: Can be set to either 0 or 1
NOTE:
1. The CM21 bit in the CM2 register has both the oscillation control and selector functions.
8.5.3
Wait Mode
In wait mode, the CPU clock and BCLK both stop running, and the CPU and watchdog timer, operated by the
CPU clock, also stop. When the PM22 bit in the PM2 register is set to 1 (on-chip oscillator clock as watchdog
timer count source), the watchdog timer continues operating. Because the main clock, sub clock, and on-chip
oscillator clock keep running, peripheral functions using these clocks also continue to operate.
To enter wait mode, execute WAIT instruction in main clock mode, low-speed mode, on-chip oscillator mode,
and on-chip oscillator low-power consumption mode.
8.5.3.1
Peripheral Function Clock Stop Function
If the CM02 bit in the CM0 register is set to 1 (peripheral function clock stops in wait mode), fAD, f1, f8, f32,
and f2n (when fPFC is used as its count source) stop in wait mode. Power consumption can be reduced. fC32,
and f2n (when the clock input to XIN or on-chip oscillator clock is used as the count source), continue running.
8.5.3.2
Entering Wait Mode
When entering wait mode with setting the CM02 bit in the CM0 register to 1, set bits MCD4 to MCD0 in the
MCD register to be the 10-MHz or less CPU clock frequency after dividing the main clock.
To enter wait mode, execute WAIT instruction while the NMI pin is held “H”.
Table 8.5
Bit Setting and Operation Mode Associated with Clocks
CPU Clock
Source
Operation Mode
Oscillation Control
Selector
CM0 Register
PLC0
Register
CM2
Register
(1)
CM1
Register
CM0
Register
PM3 Register
CM05 CM04
PLC07
CM21
CM17
CM07
PM37
PM35
Main clock
Main clock mode
0
000
0
PLL clock
Single-speed mode
0
1
010
0
1
Double-speed mode
0
1
010
1
Sub clock
Low-speed mode
0
1
10
Low-power
consumption mode
11
0
01
0
On-chip
oscillator clock
On-chip oscillator mode
0
1
00
On-chip oscillator
low-power consumption
mode
1
0
100
0