Nokia 6620 Manual Do Serviço
Issue 3 05/2005
COMPANY CONFIDENTIAL
11
Copyright © 2005 Nokia. All Rights Reserved.
NHL-12
6 - Baseband
Nokia Customer Care
3. Baseband Architecture
■
CMT side
The CMT architecture is based on DCT4 Common Baseband.
The main functionality of the CMT baseband is implemented into two ASICs: UPP (Universal
Phone Processor) and UEM (Universal Energy Management).
Phone Processor) and UEM (Universal Energy Management).
System clock for the CMT is derived from the RF circuits. For the CDMA system, the RF clock
is 19.2 MHz and for GSM it is 26 MHz. The low frequency sleep clock is generated in the UEM
using an external 32.768kHz crystal. The I/O voltage of the CMT baseband is 1.8V. The ana-
logue parts are powered from 2.8V power rails. The core voltage of UPP can be altered with
SW, depending on the prevailing processing power requirements.
is 19.2 MHz and for GSM it is 26 MHz. The low frequency sleep clock is generated in the UEM
using an external 32.768kHz crystal. The I/O voltage of the CMT baseband is 1.8V. The ana-
logue parts are powered from 2.8V power rails. The core voltage of UPP can be altered with
SW, depending on the prevailing processing power requirements.
UEM is a dual voltage circuit. The digital parts are running from the baseband supply (1.8V)
and the analogue parts are running from the analogue supply (2.8V). Some of the UEM blocks
are also connected directly to the battery voltage (VBAT). UEM includes 6 linear LDO (low
drop-out) regulator for baseband and 7 regulators for RF. It also includes 4 current sources for
biasing purposes and internal usage. Some parts of the SIM interface have been integrated into
UEM. The SIM interface supports 1.8V and 3V SIM cards. Data transmission between the UEM
and UPP is handled via two serial buses: DBUS for DSP and CBUS for MCU. There are also
separate signals for PDM coded audio. Digital speech processing is handled by the DSP inside
UPP and the audio codec is in UEM.
and the analogue parts are running from the analogue supply (2.8V). Some of the UEM blocks
are also connected directly to the battery voltage (VBAT). UEM includes 6 linear LDO (low
drop-out) regulator for baseband and 7 regulators for RF. It also includes 4 current sources for
biasing purposes and internal usage. Some parts of the SIM interface have been integrated into
UEM. The SIM interface supports 1.8V and 3V SIM cards. Data transmission between the UEM
and UPP is handled via two serial buses: DBUS for DSP and CBUS for MCU. There are also
separate signals for PDM coded audio. Digital speech processing is handled by the DSP inside
UPP and the audio codec is in UEM.
The analogue interface between the baseband and the RF sections is implemented into UEM.
UEM provides A/D and D/A conversion of the in-phase and quadrature receive and transmit
signal paths and supplies the analogue TXC and AFC signals to the RF section under the UPP
DSP control. The digital RF-BB interface, consisting of a dedicated RFIC control bus and a
group of GenIO pins, is located in UPP.
UEM provides A/D and D/A conversion of the in-phase and quadrature receive and transmit
signal paths and supplies the analogue TXC and AFC signals to the RF section under the UPP
DSP control. The digital RF-BB interface, consisting of a dedicated RFIC control bus and a
group of GenIO pins, is located in UPP.
The baseband supports both internal and external microphone inputs and speaker outputs. In-
put and output signal source selection and gain control is done in the UEM according to control
messages from the UPP. Keypad tones, DTMF and other audio tones are generated and en-
coded by the UPP and transmitted to UEM for decoding.
put and output signal source selection and gain control is done in the UEM according to control
messages from the UPP. Keypad tones, DTMF and other audio tones are generated and en-
coded by the UPP and transmitted to UEM for decoding.
NHL-12 has two galvanic serial control interfaces for CMT: FBUS and MBUS.
Communication between the APE and CMT parts is handled through two serial buses: XBUS
and XABUS. XBUS is the main communication channel for general use, and XABUS is for au-
dio data transfer. Also the system reset (PURX) and SleepClk for APE are coming from the
CMT side. The PURX is delayed approximately 130ms to fulfil OMAP1510 reset timing require-
ments and one of UEM’s IR level shifters is used for SleepClk level shifting.
and XABUS. XBUS is the main communication channel for general use, and XABUS is for au-
dio data transfer. Also the system reset (PURX) and SleepClk for APE are coming from the
CMT side. The PURX is delayed approximately 130ms to fulfil OMAP1510 reset timing require-
ments and one of UEM’s IR level shifters is used for SleepClk level shifting.