UPMU-M3L1X-B-EK Silicon Labs, UPMU-M3L1X-B-EK Datasheet - Page 45

• Manufacturer Part Number: UPMU-M3L1X-B-EK
• Description: Daughter Cards & OEM Boards UDP SiM3L1xx MCU Card (no LCD)
• Manufacturer: Silicon Labs

Specifications of UPMU-M3L1X-B-EK

• Product: MCU Cards
• Core: ARM Cortex M3
• Data Bus Width: 32 bit
• Description/function: MCU Card (No LCD) to use with UDP Motherboard
• Interface Type: I2C, SPI, UART
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Tool Is For Evaluation Of: SiM3L1xx
• For Use With: SiM3L1xx

4.6.3. Real-Time Clock (RTC0)
The RTC0 module includes a 32-bit timer that allows up to 36 hours of independent time-keeping when used with a
32.768 kHz watch crystal. The RTC0 provides three alarm events in addition to a missing clock event, which can
also function as interrupt, reset, or wakeup sources on SiM3L1xx devices.
The RTC0 module includes internal loading capacitors that are programmable to 16 discrete levels, allowing
compatibility with a wide range of crystals.
The RTC0 timer clock can be buffered and routed to a port bank pin to provide an accurate, low frequency clock to
other devices while the core is in its lowest power down mode. The module also includes a low power internal low
frequency oscillator that reduces low power mode current and is available for other modules to use as a clock
source.
The RTC0 module includes the following features:
4.6.4. Low Power Timer (LPTIMER0)
The Low Power Timer (LPTIMER0) module runs from the RTC timer clock (RTC0CLK), allowing the LPTIMER0 to
operate even if the AHB and APB clocks are disabled. The LPTIMER0 counter can increment using one of two
clock sources: the clock selected by the RTC0 module, or rising or falling edges of an external signal.
The Low Power Timer includes the following features:
4.6.5. Watchdog Timer (WDTIMER0)
The WDTIMER0 module includes a 16-bit timer, a programmable early warning interrupt, and a programmable
reset period. The timer registers are protected from inadvertent access by an independent lock and key interface.
The watchdog timer runs from the low frequency oscillator (LFOSC0).
The Watchdog Timer has the following features:
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32-bit timer (supports up to 36 hours) with three separate alarms.
Option for one alarm to automatically reset the RTC timer.
Missing clock detector.
Can be used with the internal Low Frequency Oscillator or with an external 32.768 kHz crystal (no
additional resistors or capacitors necessary).
Programmable internal loading capacitors support a wide range of external 32.768 kHz crystals.
The RTC timer clock (RTC0CLK) can be buffered and routed to an I/O pin to provide an accurate, low
frequency clock to other devices while the core is in its lowest power down mode.
The RTC0 module can be powered from the low power mode charge pump for lowest possible power
consumption while in PM8.
Runs on low-frequency RTC timer clock (RTC0TCLK).
The LPTIMER counter can increment using one of two clock sources: the RTC0TCLK or rising or falling
edges of an external signal.
Overflow and threshold-match detection.
Timer reset on threshold-match allows square-wave generation at a variable output frequency.
Supports PWM with configurable period and duty cycle.
The LPTIMER0 module can be powered from the low power mode charge pump for lowest possible power
consumption while in PM8.
Programmable timeout interval.
Optional interrupt to warn when the Watchdog Timer is nearing the reset trip value.
Lock-out feature to prevent any modification until a system reset.
Rev 0.5
SiM3L1xx
45