EFM32G200F16 Energy Micro, EFM32G200F16 Datasheet - Page 93

• Manufacturer Part Number: EFM32G200F16
• Description: MCU 32BIT 16KB FLASH 32-QFN
• Manufacturer: Energy Micro
• Series: Geckor

Specifications of EFM32G200F16

• 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: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K 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: 8 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

11.3.1 System Clocks
11.3.1.1 HFCLK - High Frequency Clock
11.3.1.2 HFCORECLK - High Frequency Core Clock
11.3.1.3 HFPERCLK - High Frequency Peripheral Clock
11.3.1.4 LFACLK - Low Frequency A Clock
2010-09-06 - d0001_Rev1.00
HFCLK is the selected High Frequency Clock. This clock is used by the CMU and drives the two
prescalers that generate HFCORECLK and HFPERCLK. The HFCLK can be driven by a high-frequency
oscillator (HFRCO or HFXO) or one of the low-frequency oscillators (LFRCO or LFXO). By default the
HFRCO is selected. In most applications, one of the high frequency oscillators will be the preferred
choice. To change the selected HFCLK write to HFCLKSEL in CMU_CMD. The HFCLK is running in
EM0 and EM1.
HFCORECLK is a prescaled version of HFCLK. This clock drives the Core Modules, which consists of
the CPU and modules that are tightly coupled to the CPU, e.g. MSC, DMA etc. This also includes the
interface to the Low Energy Peripherals. Some of the modules that are driven by this clock can be clock
gated completely when not in use. This is done by clearing the clock enable bit for the specific module
in CMU_HFCORECLKEN0. The frequency of HFCORECLK is set using the CMU_HFCORECLKDIV
register. The setting can be changed dynamically and the new setting takes effect immediately.
Note
Like HFCORECLK, HFPERCLK is also a potentially prescaled version of HFCLK. This clock drives
the High-Frequency Peripherals. All the peripherals that are driven by this clock can be clock gated
completely when not in use. This is done by clearing the clock enable bit for the specific peripheral in
CMU_HFPERCLKEN0. The frequency of HFPERCLK is set using the CMU_HFPERCLKDIV register.
The setting can be changed dynamically and the new setting takes effect immediately.
Note
LFACLK is the selected clock for the Low Energy A Peripherals. There are three selectable sources
for LFACLK: LFRCO, LFXO and HFCORECLK
reset, the LFACLK source is set to LFRCO. However, note that the LFRCO is disabled from reset. The
selection is configured using the LFA field in CMU_LFCLKSEL. The HFCORECLK
the Low Energy A Peripherals to be used as high-frequency peripherals.
Note
Each Low Energy Peripheral that is clocked by LFACLK has its own prescaler setting and enable bit.
The prescaler settings are configured using CMU_LFAPRESC0 and the clock enable bits can be found
in CMU_LFACLKEN0. Notice that the LCD has an additional high resolution prescaler for Frame Rate
Control, configured by FDIV in CMU_LCDCTRL. When operating in oversampling mode, the pulse
counters are clocked by LFACLK. This is configured for each pulse counter (n) individually by setting
PCNTnCLKSEL in CMU_PCNTCTRL.
Note that if HFPERCLK runs faster than HFCORECLK, the number of clock cycles for each
bus-access to peripheral modules will increase with the ratio between the clocks. Please
refer to Section 5.2.3.2 (p. 18) for more details.
Note that if HFPERCLK runs faster than HFCORECLK, the number of clock cycles for each
bus-access to peripheral modules will increase with the ratio between the clocks. E.g. if a
bus-access normally takes three cycles, it will take 9 cycles if HFPERCLK runs three times
as fast as the HFCORECLK.
If HFCORECLK/2 is selected as LFACLK, the clock will stop in EM2/3.
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/2. In addition, the LFACLK can be disabled. From
www.energymicro.com
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/2 setting allows