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M0A21/M0A23 Series
May 06, 2022
Page
108
of 746
Rev 1.02
M0
A21
/M
0
A
2
3
SE
RIES
TEC
H
NICAL
RE
FEREN
C
E
M
ANUAL
Idle mode
CPU enter Sleep mode
Only CPU clock is disabled.
Power-down mode
CPU enters Power-down
mode
Most clocks are disabled except LIRC/LXT, and only
WDT/Timer/UART peripheral clocks still enable if their clock
sources are selected as LIRC/LXT.
Table 6.2-2 Power Mode Table
There are different power mode entry settings and leaving condition for each power mode. Table 6.2-3
shows the entry setting for each power mode. When chip power-on, chip is running in normal mode.
User can enter each mode by setting SLEEPDEEP (SCR[2]), PDEN (CLK_PWRCT:[7]) and execute
WFI instruction.
Register/Instruction
Mode
SLEEPDEEP
(SCR[2])
PDEN
(CLK_PWRCTL[7])
CPU Run WFI Instruction
Normal mode
0
0
NO
Idle mode
(CPU enter Sleep mode)
0
0
YES
Power-down mode
(CPU enters Deep Sleep mode)
1
1
YES
Table 6.2-3 Power Mode Difference Table
There are several wake-up sources in Idle mode and Power-down mode. Table 6.2-4 lists the available
clocks for each power mode.
Power Mode
Normal Mode
Idle Mode
Power-Down Mode
Definition
CPU is in active state
CPU is in sleep state
CPU is in sleep state and all
clocks stop except LXT and
LIRC. SRAM content retended.
Entry Condition
Chip is in normal mode after
system reset released
CPU executes WFI instruction. CPU sets sleep mode enable
and power down enable and
executes WFI instruction.
Wake-up Sources
N/A
All interrupts
WDT, Timer, UART, BOD,
GPIO, EINT, USCI, CAN and
ACMP
Available Clocks
All
All except CPU clock
LXT and LIRC
After Wake-up
N/A
CPU back to normal mode
CPU back to normal mode
Table 6.2-4 Power Mode Difference Table