Figure 52 System level block diagram
Baseband functional description
Digital baseband is single processor architecture. It consists of RAP, EM ASIC (N2200), EM ASIC (N2300) and
memories as the core. RAP is a GSM EDGE chip with lots of peripheral features. Supported cellular protocols
in RAP are GSM (minimum EDGE class 10, GPRS phase2). In general RAP consists of three separate parts. The
first part is processor subsystem (PSS) that includes both MCU and DSP processors and related functions. The
second part is MCU peripherals that are peripherals mainly controlled by MCU. The third one is DSP peripherals
that are peripherals mainly controlled by DSP. N2200 is an audio ASIC including also energy management
(EM) functions. With second EM ASIC N2300, it covers the analog audio and energy management function.
N2200 is also the device that handles the power-up and power-down routines of the system. During the
times when the digital BB is alive N2200 handles a variety of tasks that can not be accomplished elsewhere
due to voltage requirements, noise etc. N2300 power IC is intended for energy management control, supply
voltage generation and charge control of mobile phone. N2300 has a step down type (buck) programmable
switch mode regulator for digital core supply generation, up (boost) switch mode regulator with current
control for led supply, charge control circuitry with integrated switch, level shifters and regulator for FBUS/
USB-OTG, and digital circuitry including registers. Stacked triple combo memory (RAM, Nor, Nand in one
package) includes 256Mbit DDR SDRAM , 256Mbit NOR Flash and 1Gbit Mux-One Nand.
Absolute maximum ratings
Signal
Min
Nom
Max
Uni
t
Notes
Battery voltage (idle)
-0.3
5.2
V
Battery voltage maximum value is
specified during charging is active
RM-88
Nokia Customer Care
System Module
Page 8 –6
COMPANY CONFIDENTIAL
Issue 1
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