EFM32G200F64 Energy Micro, EFM32G200F64 Datasheet - Page 96

• Manufacturer Part Number: EFM32G200F64
• Description: MCU 32BIT 64KB FLASH 32-QFN
• Manufacturer: Energy Micro
• Series: Geckor

Specifications of EFM32G200F64

• 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: 64KB (64K x 8)
• Program Memory Type: FLASH
• Ram Size: 16K 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: EFM32G200
• Core: ARM Cortex-M3
• Data Bus Width: 32 bit
• Data Ram Size: 16 KB
• Interface Type: I2C, UART
• Maximum Clock Frequency: 32 MHz
• Number Of Programmable I/os: 24
• Number Of Timers: 2
• Operating Supply Voltage: 1.8 V to 3.8 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

11.3.3 Oscillator Configuration
11.3.3.1 HFXO and LFXO
2010-09-06 - d0001_Rev1.00
Figure 11.3. CMU Switching from HFRCO to HFXO after HFXO is ready
Switching clock source for LFACLK and LFBCLK is done by setting the LFA and LFB fields in
CMU_LFCLKSEL. To ensure no stalls in the Low Energy Peripherals, the clock source should be ready
before switching to it.
Note
The crystal oscillators are by default configured to ensure safe startup of all crystals. In order to
optimize startup time and power consumption for a given crystal, it is possible to adjust the gain in
the oscillator by programming the LFXOBOOST and HFXOBOOST fields in CMU_CTRL for LFXO and
HFXO respectively.
The HFXO crystal is connected to the HFXTAL_N/HFXTAL_P pins as shown in Figure 11.4 (p. 96)
Figure 11.4. HFXO Pin Connection
Similarly, the LFXO crystal is connected to the LFXTAL_N/LFXTAL_P pins as shown in Figure 11.5 (p.
97)
CMU_OSCENCMD.HFRCODIS
CMU_OSCENCMD.HFRCOEN
CMU_OSCENCMD.HFXODIS
CMU_OSCENCMD.HFXOEN
CMU_STATUS.HFRCORDY
CMU_STATUS.HFRCOENS
CMU_STATUS.HFRCOSEL
CMU_STATUS.HFXORDY
CMU_STATUS.HFXOENS
CMU_STATUS.HFXOSEL
CMU_CMD.HFCLKSEL
To save energy, remember to turn off all oscillators not in use.
HFRCO
HFCLK
HFXO
C
L1
4-32 MHz
HFXO tim e-out period
C
L2
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HFXTAL_N
HFXTAL_P
EFM32
02
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