Introduction
15-5
Clock Generation and System Reset Management
15.1.1.1
ULPD Module
The ULPD module is an embedded peripheral controlled by the internal MPU
with the following functions:
-
Performs the state transition of the different power modes:
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Awake: 32-kHz and 12-MHz clocks are on, and 12 MHz is fed into the
clock generation module (those PLLs can be turned on or off).
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Big sleep mode: 32-kHz and 12-MHz clocks are on, 12 MHz is not fed
into the clock generation module, and PLLs are off.
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Deep sleep mode: 32-kHz clock is on, and 12-MHz clock and PLLs are
off.
-
Performs the power-on reset of the chip
-
Calibrates an external quartz based oscillator (32 kHz)
-
Performs the wake up of the 12-MHz OSC1 oscillator to provide the OSC1
clock to an external device. An external clock request or peripheral wake-
up request turns on the OSC1 oscillator but is not treated as an interrupt.
-
Performs a 12-MHz/32-kHz switch for peripherals that need to switch to
32 kHz
-
Generates the functional reset signal used by the reset module
-
Manages the 48-MHz DPLL and APLL on/off
-
Processes battery-failed signal to generate external shutdown signal
(RST_HOST_OUT)
15.1.1.2
Reset Module
The reset module has the following functions:
-
Provides internal global reset and software reset
-
Performs reset control for peripheral bus peripherals
-
Monitors internal and external reset (for example, watchdog timer
time-out)
-
Monitors system and reset status