System Overview - LG GB195 Service Manual

3.1.1 System overview

MT6223 is an entry level chipset solution with class 12 GPRS/GSM modem. It integrates only
only analog baseband but also power management blocks into one chip and can greatly reduce
the component count and make smaller PCB size. Besides, MT6223 is capable of SAIC (Single
Antenna Interference Cancellation) and AMR speech. Based on 32 bit ARM7EJ-STM RISC
processor, MT6223 provides an unprecedented platform for high quality modem performance.
Platform
MT6223 runs the ARM7EJ-STM RISC processor at up to 52Mhz, thus providing best
trade-off between system performance and power consumption.
For large amount of data transfer, high performance DMA (Direct Memory Access) with
hardware flow control is implemented, which greatly enhances the data movement speed while
reducing MCU processing load.
Targeted as a modem-centric platform for mobile applications, MT6223 also provides
hardware security digital rights management for copyright protection. For further safeguarding,
and to protect manufacturer's development investment, hardware flash content protection
is also provided to prevent unauthorized porting of software load.
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Memory
MT6223 supports up to 4 external state-of-the-art devices through its 8/16-bit host interface.
Devices such as burst/page mode Flash, page mode SRAM, and Pseudo SRAM are supported.
For greatest compatibility, the memory interface can also be used to connect to legacy devices
such as Color/Parallel LCD, and multi-media companion chip are all supported through this
interface. To minimize power consumption and ensure low noise, this interface is designed for
flexible I/O voltage and allows lowering of supply voltage down to 1.8V. The driving strength is
configurable for signal integrity adjustment. The data bus also employs retention technology to
prevent the bus from floating during turn over.
Multi-media
MT6223 utilize high resolution audio DAC, digital audio, and audio synthesis technology to
provide superior audio features., e.g. MP3 ring tone. For MT6223C, MP3 player is also
supported.
Connectivity, and Storage
MT6223 supports UART as well as Bluetooth interface. Also, necessary peripheral blocks are
embedded for a voice centric phone: Keypad Scanner with the capability to detect multiple key
presses, SIM Controller, Alerter, Real Time Clock, PWM, Serial LCD Controller, and General
Purpose Programmable I/Os.
Furthermore, to provide more configuration and bandwidth for display, an additional 9-bit
parallel interface is incorporated.
For MT6223C, memory card control is provided through LCD interface, including SD and mini
SD, etc. Therefore high quality MP3 playback of 48kHz sampling with 320kbps format can be
supported
Audio
Using a highly integrated mixed-signal Audio Front-End, architecture of MT6223 allows for
easy audio interfacing with direct connection to the audio transducers. The audio interface
integrates D/A and A/D Converters for Voice band, as well as high resolution Stereo D/A
Converters for Audio band. In addition, MT6223 also provides Stereo Input and Analog Mux.
MT6223 also supports AMR codec to adaptively optimize speech and audio quality.
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