EFM32LG995F256 Energy Micro, EFM32LG995F256 Datasheet - Page 4

• Manufacturer Part Number: EFM32LG995F256
• Description: ARM Microcontrollers - MCU 256KB FL 32KB RAM
• Manufacturer: Energy Micro

Specifications of EFM32LG995F256

• Rohs: yes
• Core: ARM Cortex M3
• Processor Series: Leopard Gecko (LG)
• Data Bus Width: 32 bit
• Maximum Clock Frequency: 48 MHz
• Program Memory Size: 256 KB
• Data Ram Size: 32 KB
• On-chip Adc: Yes
• Operating Supply Voltage: 1.85 V to 3.8 V
• Operating Temperature Range: - 40 C to + 85 C
• Package / Case: BGA-120
• Mounting Style: SMD/SMT
• A/d Bit Size: 12 bit
• Interface Type: I2C, SPI, USB, UART
• Number Of Programmable I/os: 93
• Program Memory Type: Flash

2.1.4 Direct Memory Access Controller (DMA)
2.1.5 Reset Management Unit (RMU)
2.1.6 Energy Management Unit (EMU)
2.1.7 Clock Management Unit (CMU)
2.1.8 Watchdog (WDOG)
2.1.9 Peripheral Reflex System (PRS)
2.1.10 External Bus Interface (EBI)
2.1.11 TFT Direct Drive
2012-09-11 - EFM32LG995FXX - d0124_Rev1.00
into two blocks; the main block and the information block. Program code is normally written to the main
block. Additionally, the information block is available for special user data and flash lock bits. There is
also a read-only page in the information block containing system and device calibration data. Read and
write operations are supported in the energy modes EM0 and EM1.
The Direct Memory Access (DMA) controller performs memory operations independently of the CPU.
This has the benefit of reducing the energy consumption and the workload of the CPU, and enables
the system to stay in low energy modes when moving for instance data from the USART to RAM or
from the External Bus Interface to a PWM-generating timer. The DMA controller uses the PL230 µDMA
controller licensed from ARM.
The RMU is responsible for handling the reset functionality of the EFM32LG.
The Energy Management Unit (EMU) manage all the low energy modes (EM) in EFM32LG microcon-
trollers. Each energy mode manages if the CPU and the various peripherals are available. The EMU
can also be used to turn off the power to unused SRAM blocks.
The Clock Management Unit (CMU) is responsible for controlling the oscillators and clocks on-board
the EFM32LG. The CMU provides the capability to turn on and off the clock on an individual basis to all
peripheral modules in addition to enable/disable and configure the available oscillators. The high degree
of flexibility enables software to minimize energy consumption in any specific application by not wasting
power on peripherals and oscillators that are inactive.
The purpose of the watchdog timer is to generate a reset in case of a system failure, to increase appli-
cation reliability. The failure may e.g. be caused by an external event, such as an ESD pulse, or by a
software failure.
The Peripheral Reflex System (PRS) system is a network which lets the different peripheral module
communicate directly with each other without involving the CPU. Peripheral modules which send out
Reflex signals are called producers. The PRS routes these reflex signals to consumer peripherals which
apply actions depending on the data received. The format for the Reflex signals is not given, but edge
triggers and other functionality can be applied by the PRS.
The External Bus Interface provides access to external parallel interface devices such as SRAM, FLASH,
ADCs and LCDs. The interface is memory mapped into the address bus of the Cortex-M3. This enables
seamless access from software without manually manipulating the IO settings each time a read or write
is performed. The data and address lines are multiplexed in order to reduce the number of pins required
to interface the external devices. The timing is adjustable to meet specifications of the external devices.
The interface is limited to asynchronous devices.
The EBI contains a TFT controller which can drive a TFT via a 565 RGB interface. The TFT controller
supports programmable display and port sizes and offers accurate control of frequency and setup and
Preliminary
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