Nokia RM307, 2505 Baseband Description and Troubleshooting

Nokia Customer Care

2505 (RM-307)

Mobile Terminal

Baseband Description and

Troubleshooting

2505 (RM-307) Baseband Description and Troubleshooting

Contents Page

Introduction............................................................................................................... 3

Baseband and Power Management Architecture .................................................... 4

Power Up and Reset ................................................................................................ 5

Power Up .......................................................................................................6

Power Off.......................................................................................................7

Power Consumption and Operation Modes ...................................................7

Power Distribution .................................................................................................... 8

Clock Distribution...................................................................................................... 9

System Clocks .............................................................................................10

TCXO........................................................................................................... 11

SLEEP Crystal Circuit for 32.768 kHz..........................................................12

SBI CLK Interface ........................................................................................14

Flash Programming Error Description.................................................................... 14

Charging Operation ................................................................................................ 15

Battery .........................................................................................................15

Charging Circuitry ........................................................................................15

Charger Detection........................................................................................16

Charge Control ............................................................................................17

Audio ...................................................................................................................... 17

Display and Keyboard ............................................................................................ 18

Accessories ............................................................................................................ 18

Charging ......................................................................................................19

Headset Detection .......................................................................................19

RUIM CARD ........................................................................................................... 19

Test Points – Top ................................................................................................... 20

Troubleshooting...................................................................................................... 22

Mobile Terminal is Dead...............................................................................23

Flash Faults .................................................................................................24

Power Does Not Stay ON or the Mobile Terminal is Jammed ......................25

Charger Faults .............................................................................................26

Audio Faults.................................................................................................27

Display Faults ..............................................................................................31

Keypad Faults..............................................................................................32

Keypad Faults..............................................................................................33

2505 (RM-307)

Nokia Customer Care Baseband Description and Troubleshooting

Introduction

The mobile terminal using a CDMA single mode engine (Cellular/ 800) with

Qualcomm baseband consists of the following ASICs:

●Qualcomm Single Chip 6010, including RF transmitter and receiver,

Baseband and Power management these three categories

●64Mb Flash memory with 16Mb of Psram memory

The baseband is consisted of an Arm926EJ-S processor, a CDMA processor, two

QDSP4000 processors, Codec, Analog interface for RF and controllers for GPIOs,

UART, EBI, RUIM & peripheral interfaces, all of which are necessary to complete the

entire CDMA baseband system. The ARM926EJ-S is a high-performance, low-power

microprocessor. The features of the ARM microprocessor include a 3-stage pipelined

RISC architecture, both 32-bit ARM and 16-bit THUMB instruction sets, a 32-bit

address bus, and a 32-bit internal data bus. The two low-power, high-performance

QDSP4000 digital signal processor cores, one is for the modem (mDSP) that

dedicated to modem functions and CDMA signal processing, and the other is for

applications (aDSP) such as all vocoder functions, audio application, and CMX.

QSC6010 has two Advanced High-speed Bus (AHB),a fast peripheral bus (FPB), and

two Mobile Station Modem(MSM) bridge. Main AHB bus is controlled by the ARM926

for data and instructions. Second AHB allows mDSP and aDSP to access external

peripherals via DME interfaces. The FPB offloads the Main AHB so that a high

number of slaves does not limit its bus speed. MSM bus bridges support peripherals

that do not have an AHB interface.

The mobile terminal supports standard Nokia 2-wire and 3 wire chargers (AC-3, AC-4,

DC-4). However, the 3-wire chargers are treated as 2-wire chargers. The pulse

width modulation (PWM) controls signal for controlling the 3-wire charger is ignored.

The MSM and PM energy management software control the charging.

BL-4B (700 mAh) lithium-ion battery is used as the main power source.

2505 (RM-307) Baseband Description and Troubleshooting

Baseband and Power Management Architecture

Figure 1: Baseband Diagram

Figure 2: Power Management of QSC6010

2505 (RM-307)

Nokia Customer Care Baseband Description and Troubleshooting

Power Up and Reset

The QSC6010 controls the power up and reset. The baseband can power up in the

following ways:

z Pressing the Power button, which means to ground the KPD_PWR_N

(“PHONE_ON_N” pin in 2505 schematic) pin of the QSC6010

z Connecting the charger to the charger input.

After receiving one of the above signals, the PM will start to enter reset mode. The

watchdog starts, and if the battery voltage is greater than its threshold (3V), a 6ms

delay starts to allow MSM to settle. After this delay elapses, the VERG_MSMC

regulator enables. Then, VERG_MSMP, VERG_MSMA & VERG_TCXO regulators

are enabled in sequence after MSMC. There is a 120us (4 Sleep_Clocks) delays

between each regulator’s turn on. The PON_RESET_N (“RESIN_N” pin in 2505

schematic) line holds low for another 20ms and is sent to MSM. Resets are

generated for the MSM’s internal MCU and its internal DSP, and MSM sends

TCXO_ON (“TCXO_EN” pin in 2505 schematic) signal to PM to enable TCXO. After

PON_RESET_N goes high, MSM holds PS_HOLD at low state for 200ms and then

drives PS_HOLD to high state. This will keep all regulators at on state in order to

complete this power on sequence. KPD_PWR_N key can be released after

PS_HOLD goes high.

The RESOUT_N from QSC6010 is used to reset flash memory during power up and

to put the flash memory in power down during sleep mode. LCD_RS from QSC6010

is used to reset LCD module during power up. All baseband regulators are switched

on when the PM is powered on. The QSC6010’s internal watchdog runs and resets

during normal operation. If the watchdog expires, it will generate a reset signal to

reset to MSM status. Then, QSC6010 drives RESOUT_N and LCD_RS low to reset

flash memory and LCD module.

Figure 3 represents the PM start-up sequence from reset to power-on.

2505 (RM-307) Baseband Description and Troubleshooting

Figure 3: Power-on & off sequence and timing

Power Up

The mobile terminal can use the power key or a charger to power up.

Power Key

When the power key is pressed, the PM enters the power-up sequence. Pressing the

power key causes the KPD_PWR_N (PHONE_ON_N pin in 2505 schematic) pin to

GND. The KPD_PWR_N signal is not part of the keypad matrix. The power key is

only connected to the PM. This means that when the power key is pressed, an

interrupt will be generated to the MSM in order to power on the MCU. The MCU

reads the QSC6010’s interrupt register and notifies that it is a KPD_PWR_N interrupt.

The MCU reads the status of the KPD_PWR_N signal using the control bus. If the

KPD_PWR_N signal stays low for a certain time, the MCU accepts this as a valid

power-on state and continues with the software baseband initialization. If the power

key does not indicate a valid power-on situation, the MCU powers off the baseband.

Charger

Charging is controlled by start-up charging circuitry in order to detect and start

charging in cases the main battery is empty and the PM has no supply.

External Supply Source is Detected

If a valid source is applied to VCHG (pin V15 of QSC6010) and the battery voltage of

VPH_PWR exceeds PM’s valid UVLO (2.5V) threshold, the power-on sequence of

PM is initiated and enables its internal regulators. UVLO is the minimum voltage

required for QSC6010 operation. If the entire power-on sequence is successful, the

appropriate interrupt from PM will be sent to the MSM. Once the battery voltage rises

2505 (RM-307)

Nokia Customer Care Baseband Description and Troubleshooting

above 3.0V (min. MSM operation voltage), code start running on MSM. The MSM

reads PM registers to identify the power source and whether battery charging is

required. If a valid supply voltage is applied while the PM is on, the power-on

sequence is skipped. A charging sequence will then be initiated.

Power Off

While the PS_HOLD signal from the MSM is high, and the PM is in one of its

power-on states. Under this condition, the PM continually monitors three events that

could trigger a power-off sequence:

The MSM drives the PS_HOLD signal low responding to the pressing of the

keypad power button.

z Battery voltage drops below power off threshold (Battery voltage < 3.2 V).

z The PM die temperature exceeds its “severe” over-temperature threshold.

Power Consumption and Operation Modes

Power-off Mode

In power-off mode, power (VPH_PWR) is supplied to the PM, RF PA, vibrator, and

keypad backlight LED. During this mode, the current consumption is approximately

8.8 uA.

Sleep Mode

The mobile terminal enters sleep mode only when MSM makes the request to PM

through the SBI bus. PM then enters Power Saving Mode, and the VREG_MSMC

VREG_MSMP regulators remain in power-on stage. The 32.768 kHz crystal is

enabled. TCXO buffers are off. All other functions and regulators are controlled

individually via SBI and are typically disabled for minimum power dissipation.

It exits the Sleep mode either by the expiration of a sleep clock counter in the PM or

by some external interrupt (generated by a charger connection, key press, headset

connection, etc.). The TCXO is shut down in sleep mode and the 32.768 kHz sleep

clock oscillator is used as a reference clock for the baseband.

Active Mode

In active mode, the mobile terminal operates normally. It scans channels, listens to a

base station, transmits and processes information. There are several sub-states

under the active mode. Depending on the mobile terminal’s current state, there are

states such as burst reception, burst transmission, etc.

2505 (RM-307) Baseband Description and Troubleshooting

In active mode, this is a normal operating mode for PM. VREG_MSMC,

VREG_MSMP, VREG_MSMA, VREG_RUIM, VREG_RFRX, VREG_RFTX, and

VREG_TCXO regulators are all turned on. TCXO oscillator is enabled, and TCXO

buffers are turned on. All other functions and regulators are controlled individually via

SBI.

Charging Mode

Charging mode can function in parallel with any other operating mode. A BSI resistor

inside the battery pack indicates the battery type/ size. The resistor value

corresponds to a specific battery capacity. The PM measures the battery voltage,

temperature, size, and charging current.

Charger control block inside the PM controls the charging current delivered from the

charger to the battery and mobile terminal. The maximum battery voltage is limited

by turning the PM switch off when the battery voltage reaches 4.2 V. The charging

current is monitored by measuring the voltage drop across a 0.1 ohm resistor.

Power Distribution

In normal operation, the baseband is powered by the mobile terminal‘s battery pack.

The battery pack consists of one lithium-ion cell with a capacity of 820 mAh and

safety and protection circuits.

The PM controls the power distribution to the whole mobile terminal, which includes

the baseband and the RF regulators, but excludes the RF power amplifier (RF PA)

RF power amplifier drains power from the battery directly. The battery provides

power directly to the following parts of the system:

z PM

z RF PA

z Vibrator

z Keyboard , Electric torch light& LCD backlights

The heart of the power distribution is the power control block inside the PM. It

includes all the voltage regulators and feeds the power to the entire system. The PM

handles hardware power-up functions so that the regulators are not powered on and

the power up reset (PURX) is not released if the battery voltage is less than 3 V.

2505 (RM-307)

Nokia Customer Care Baseband Description and Troubleshooting

The baseband is powered by the following PM regulators:

Regulator

MSMC 500 mA 1.2 V Always enabled except during power-off mode

MSMA 150 mA 2.60 V

MSMP 300 mA 2.60 V Always enabled except during power-off mode

RUIM 150 mA 3.00 V Enabled only when RUIM card is used

TCXO 50 mA 2.85 V

Note: All output regulators voltage accuracy +/-2%

Table 2 includes the PM regulators for the RF.

Regulator

RFRX 150 mA 2.60 V Enabled when the receiver is on

Rating

Current

Rating

Current

Voltage Notes

Enabled only when the system is powered on (Off during sleep and power-off modes)

Table 1: Baseband Regulators

Voltage Notes

RFTX 150 mA 2.60 V Enabled when the transmitter is on

Note: All output regulators voltage accuracy +/-2%

Table 2: RF Regulators

Clock Distribution

The QSC6010 derives its internal clock from two clock inputs, TCXO and

SLEEP_CLK.

The main clock signal for the baseband generates from TCXO

(Temperature-compensated crystal oscillator). The QSC6010’s TCXO clock input

supports the frequency 19.2 MHz +/-2ppm. The SLEEP_CLK provides a 32.768 kHz

+/-20ppm clock source to drive the MSM controller into sleep mode. At this mode,

most of the MSM is powered down and the TCXO is disabled.

2505 (RM-307) Baseband Description and Troubleshooting

System Clocks

The PM includes several clock circuits (Figure 4), whose outputs are used for

general housekeeping, MSM and RF functions within the mobile terminal system.

Figure 4: TCXO & SLEEP_XTAL Block Diagram

2505 (RM-307)

Nokia Customer Care Baseband Description and Troubleshooting

TCXO

The MSM device integrates a phase-locked loop from the TCXO clock input.

The PM optimizes TCXO operation that enables and disables appropriate circuits in

the proper sequence. The controller is enabled by the signal from the MSM.

When the selected transition occurs at TCXO_EN, the controller quickly enables the

TCXO regulator and the input buffer, and begins counting SLEEP_CLK pulses.

Within an initial power on period, the TCXO will be stabilized to its own calibrated

frequency. This initial period, in units of 32.768 kHz clock pulses, is programmed into

a timer within the controller. When the timer expires, the output buffer is enabled. It

synchronizes with the TCXO input such that the TCXO_OUT signal is glitch free,

only valid TCXO pulses are output.

Figure 5: TCXO Enable Timing Diagram

The input buffer (TCXO_IN) accepts sinusoidal or square wave signals at or near

19.2 MHz. The input buffer (TCXO_IN) is powered from the TCXO regulator while

the output buffer is powered by VREG_MSMP.

The regulator of TCXO is turned off after the TCXO_EN signal is removed. Upon

power-up, the PM defaults to this SBI-controlled mode with the TCXO defaulted on.

This assures the MSM will always have a clock available immediately at power-up

even if TCXO_EN is low.

TCXO waveform (19.2MHz +/-2ppm)

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Nokia RM307, 2505 Baseband Description and Troubleshooting

Specifications and Main Features

Frequently Asked Questions

User Manual

Contents Page

Baseband and Power Management Architecture

Power Up and Reset

Power Up

Power Key

Charger

External Supply Source is Detected

Power Off

Power Consumption and Operation Modes

Power-off Mode

Sleep Mode

Active Mode

Charging Mode

Power Distribution

Clock Distribution

System Clocks

TCXO