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M0A21/M0A23 Series
May 06, 2022
Page
107
of 746
Rev 1.02
M0
A21
/M
0
A
2
3
SE
RIES
TEC
H
NICAL
RE
FEREN
C
E
M
ANUAL
The CHIP Reset is same with Power-on Reset. The CPU and all peripherals are reset and
BS(FMC_ISPCTL[1]) bit is automatically reloaded from CONFIG0 setting. User can set the
CHIPRST(SYS_IPRST0[0]) to 1 to assert the CHIP Reset signal.
The MCU Reset is similar with CHIP Reset. The difference is that BS(FMC_ISPCTL[1]) will not be
reloaded from CONFIG0 setting and keep its original software setting for booting from APROM or
LDROM. User can set the SYSRESETREQ(AIRCR[2]) to 1 to assert the MCU Reset.
6.2.3
System Power Distribution
In this chip, power distribution is divided into three segments:
Analog power from V
DD
and V
SS
provides the power for analog components operation.
Digital power from V
DD
and V
SS
supplies the power to the internal regulator which
provides a fixed 1.8V power for digital operation and I/O pins.
The outputs of internal voltage regulators, LDO and V
DD
, require an external capacitor which should be
located close to the corresponding pin. Figure 6.2-7 shows the NuMicro
®
M0A21/M0A23 power
distribution.
V
D
D
V
SS
38.4 kHz
LIRC
Oscillator
SRAM
IO Cell
V
DD
to
1.8V LDO
POR50
POR18
4~24 MHz
crystal
oscillator
Digital Logic
Flash
Power On
Control
XT1_OUT
(PA.5)
XT1_IN
(PA.4)
1.8V
Brown-out
Detector
Low Voltage
Reset
12-bit ADC
Analog
Comparator
48 MHz
HIRC48
Oscillator
32.768 kHz
crystal
oscillator
X32_IN
(PA.4)
X32_OUT
(PA.5)
Temperature
Sensor
DAC
Figure 6.2-7 NuMicro
®
M0A21/M0A23 Power Distribution Diagram
6.2.4
Power Modes and Wake-up Sources
The M0A21/M0A23 series has power manager unit to support several operating modes for saving
power. Table 6.2-2 lists all power mode in the M0A21/M0A23 series.
Mode
CPU Operating Maximum
Speed( MHz)
Clock Disable
Normal mode
48
All clocks are disabled by control register.