EFM32TG210F32 Energy Micro, EFM32TG210F32 Datasheet - Page 272

• Manufacturer Part Number: EFM32TG210F32
• Description: MCU 32BIT 32KB FLASH 32-QFN
• Manufacturer: Energy Micro
• Series: Tiny Geckor

Specifications of EFM32TG210F32

• Core Processor: ARM® Cortex-M3™
• Core Size: 32-Bit
• Speed: 32MHz
• Connectivity: EBI/EMI, I²C, IrDA, SmartCard, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Number Of I /o: 24
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.8 V
• Data Converters: A/D 4x12b, D/A 1x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-VQFN Exposed Pad
• Processor Series: EFM32
• Core: ARM Cortex-M3
• Data Bus Width: 32 bit
• Data Ram Size: 32 KB
• Interface Type: UART, I2C, SPI
• Maximum Clock Frequency: 32 MHz
• Number Of Programmable I/os: 17
• Number Of Timers: 1
• Operating Supply Voltage: 1.8 V to 3.8 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Processor To Be Evaluated: EFM32TG210
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

18.3.1 Counter
18.3.1.1 Clock Source
2010-12-21 - d0034_Rev0.90
Figure 18.1. RTC Overview
The RTC is enabled by setting the EN bit in the RTC_CTRL register. It counts up as long as it is
enabled, and will on an overflow simply wrap around and continue counting. The RTC is cleared when it
is disabled. The timer value is read-only and the RTC always starts counting from 0 when enabled. The
value of the counter can be read using the RTC_CNT register.
The RTC clock source and its prescaler value are defined in the Register Description section of the Clock
Management Unit (CMU). The clock used by the RTC has a frequency given by Equation 18.1 (p. 272) .
RTC Frequency Equation
where f
273) shows the time of overflow and resolution of the RTC at the available prescaler values.
To use this module, the LE interface clock must be enabled in CMU_HFCORECLKEN0 in addition to
the module clock
LFACLK
LFACLK
RTC
Clear
Counter (CNT)
is the LFACLK frequency (32.768 kHz) and RTC_PRESC is a 4 bit value. Table 18.1 (p.
Com pare 0
(COMP0)
f
RTC
=
= f
Peripheral bus
LFACLK
/2
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272
RTC_PRESC
Com pare 1
(COMP1)
=
RTC Control and
Status
Com pare m atch 0
Com pare m atch 1
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(18.1)