EFM32G200F16 Energy Micro, EFM32G200F16 Datasheet - Page 412

• 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

29.3 Functional Description
29.3.1 LCD Driver Enable
29.3.2 Multiplexing, Bias, and Wave Settings
2010-09-06 - d0001_Rev1.00
An overview of the LCD module is shown in Figure 29.1 (p. 412) . In its simplest form, an LCD driver
would apply a voltage above a certain threshold voltage in order to darken a segment and a voltage below
threshold to make a segment clear. However, the LCD display segment will degrade if the applied voltage
has a DC-component. To avoid this, the applied waveforms are arranged such that the differential voltage
seen by each segment has an average value of zero, and such that the RMS voltage (or differential sum
of the two waveforms for fast response LCDs) is below the segment threshold voltage if the segment
shall be transparent, and above the segment threshold voltage when the segment shall be dark.
The waveforms are multiplexed between four different common lines and 40 segment lines to support
up to 160 different LCD segments. The common lines and segment lines can be enabled or disabled
individually to prevent the LCD driver from occupying more I/O resources than required.
Figure 29.1. LCD Block Diagram
For simplicity, only one segment pin and one common terminal is shown in the figure.
Setting the EN bit in LCD_CTRL enables the LCD driver. The MUX bitfield in LCD_DISPCTRL
determines which COM lines are driven by the LCD driver. By default, LCD_COM0 is driven whenever
the LCD driver is enabled.
The LCD_SEGEN register determines which segment lines are enabled. Segment lines can be enabled
or disabled in groups of 4.
Each LCD segment pin can also be individually disabled by configuring the pin as input in the GPIO.
Note that this feature is not available on EFM32G revisions A and B.
The LCD driver supports different multiplexing and bias settings, and these can be set individually in
the MUX and BIAS bits in LCD_DISPCTRL respectively, see Table 29.1 (p. 413) and Table 29.2 (p.
413) .
LFACLK
LCD
LCD control and
LCD anim ation
LCD segm ent
data register
registers
status
Display data
Mux and fram erate setting
Special
effects
Contrast and bias setting
sequence
generator
V
INT
LCD
...the world's most energy friendly microcontrollers
generator
412
voltage
LCD
V
BOOST
V
EXT
VLCDSEL
V
V
V
V
V
V
V
V
LC3
LC2
LC1
LC0
LC3
LC2
LC1
LC0
COM out
SEG out
Disable
Disable
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LCD_COMx
LCD_SEGx
LCD_BCAP_N
LCD_BCAP_P
LCD_BEXT
40x
4x