Baseband functional description

Digital baseband consists of an ISA (Intelligent Software Architecture) based modem and Symbian based application sections. The modem functionality is in RAP, and the application processor acts as a platform for Symbian applications. The terms ISA and Symbian are used refer to the software environment of these devices.

The modem section consists of a RAP ASIC with NOR FLASH and SDRAM memory as the core. RAP supports WCDMA and GSM cellular protocols. The modem DDR SDRAM memory has 128 Mbits of memory and NOR flash has 128 Mbits of memory. RAP operates with the system clock of 38.4 MHz, which comes from the VCTCXO.

The application section includes an application processor ASIC with DDR/NAND combo memory as the core. Application processor

The application processor is also called an application ASIC because it is processing application SW and handles the UI SW. It consists of the application processor and peripheral subsystems such as camera, display and keyboard driver blocks.

In addition to interfaces mentioned above, the peripherals block includes several different I/O interfaces, for example, for keyboard, modem chip, audio, Bluetooth and so on.

Absolute maximum ratings

Signal

Min

Nom

Max

Uni t

Notes

Battery voltage (idle)

-0.3

+4.5

V

Battery voltage maximum value is specified during charging is active

Battery voltage (Call)

+3.2

+4.3

V

Battery voltage maximum value is specified during charging is active

Charger input voltage

-0.3

+20

V

Back-Up supply voltage

0

2.5

2.6

V

Maximum capacity of the backup power supply assumed to be 10 pAh.

Phone modes of operation

Mode

Description

NO_SUPPLY

(dead) mode means that the main battery is not present or its voltage is too low (below EM ASIC N2200 master reset threshold) and that the back-up battery voltage is too low.

BACK_UP

The main battery is not present or its voltage is too low but back-up battery voltage is adequate and the 32kHz oscillator is running (RTC is on).

PWR_OFF

In this mode (warm), the main battery is present and its voltage is over EM ASIC N2200 master reset threshold. All regulators are disabled, PurX is on low state, the RTC is on and the oscillator is on. PWR_OFF (cold) mode is almost the same as PWR_OFF (warm), but the RTC and the oscillator are off.

RESET

RESET mode is a synonym for start-up sequence. In this mode certain regulators are enabled and after they and RFClk have stabilized, the system reset (PurX) is released and PWR_ON mode entered. RESET mode uses 32kHz clock to count the REST mode delay (typically 16ms).

SLEEP

SLEEP mode is entered only from PWR_ON mode with the aid of SW when the system's activity is low.

FLASHING

FLASHING mode is for SW downloading.

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