
3 Baseband
3.1 Baseband Overview
E146 Baseband consists of CPU MT6253 and Program Memory. MT6253
baseband, the core device of the mainboard, is responsible for the normal work
among various parts of mainboard, such as voice processing, image processing,
power management as well as MS communications.
MT6253 digital baseband contains ARM7EJ-S 32-bit core and 144Kbyte SRAM.
MT6253 which is an enhanced GSM Processor integrated Channel Codec
subsystems interiorly including Channel Codec, Intertlace / Deinterleave,
Encryption / Decryption and Control Processor subsystems including ARM7EJ-S
and its peripheral circuits. There are 25 address lines,16 data lines, 8 chip select
lines, provided 7 external interrupt Interface, 52M/104M operation clock.
Analog baseband contains MT6253 analog baseband chip, audio, baseband
codec and power management. Four major functional blocks integrated internal:
Audio codec including Voice input / Output channel, Buzzer output; Baseband
codec including Differential I, Q input / output, GMSK modulation and A / D, D / A;
Auxiliary parts including AFC DAC, RAMP DAC, AGC DAC and a seven-channel
A / D. And WATCHDOG interface is set internal to enhance the stability of the
system.