5/339 MediaTek Inc. Confidential
1. System Overview
MT6223D is an entry level chipset solution with class 12
GPRS/GSM modem. It integrates not only analog baseband
but also power management blocks into one chip and can
greatly reduce the component count and make smaller PCB
size. Besides, MT6223D is capable of SAIC (Single
Antenna Interference Cancellation) and AMR speech.
Based on 32 bit ARM7EJ-S
TM
RISC processor, MT6223D
provides an unprecedented platform for high quality modem
performance.
Typical application diagram is shown in Figure 1.
Platform
MT6223D runs the ARM7EJ-S
TM
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, MT6223D 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.
Memory
MT6223D supports up to 2 external state-of-the-art devices
through its 16-bit host interface. Devices such as burst/page
mode Flash, page mode SRAM, and Pseudo SRAM are
supported. 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
MT6223D utilize high resolution audio DAC, digital audio,
and audio synthesis technology to provide superior audio
features., e.g. MP3 ring tone.
Connectivity, and Storage
MT6223D 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.
Audio
Using a highly integrated mixed-signal Audio Front-End,
architecture of MT6223D 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, MT6223D also provides Stereo Input and
Analog Mux. MT6223D also supports AMR codec to
adaptively optimize speech and audio quality.
Radio
MT6223D integrates a mixed-signal Baseband front-end in
order to provide a well-organized radio interface with
flexibility for efficient customization. It contains gain and
offset calibration mechanisms, and filters with
programmable coefficients for comprehensive compatibility
control on RF modules. This approach also allows the usage
of a high resolution D/A Converter for controlling VCXO
or crystal, thus reducing the need for expensive TCVCXO.
MT6223D achieve great MODEM performance by utilizing
14-bit high resolution A/D Converter in the RF downlink
path. Furthermore, to reduce the need for extra external
current-driving component, the driving strength of some
BPI outputs is designed to be configurable.
Debug Function
The JTAG interface enables in-circuit debugging of
software program with the ARM7EJ-S core. With this
standardized debugging interface, MT6223D provides
developers with a wide set of options in choosing ARM
development kits from different third party vendors.
Low Power Features
MT6223D offers various low-power features to help reduce
system power consumption. These features include Pause
Mode of 32KHz clocking at Standby State, Power Down
Mode for individual peripherals, and Processor Sleep Mode.
In addition, MT6223D are also fabricated in advanced low
leakage CMOS process, hence providing an overall ultra
low leakage solution.
Power Management
