Nokia 2118 Service Manual 08rh77bb

Nokia Customer Care

2118 (RH-77)

Mobile Terminal

Baseband Description and

Troubleshooting

2118 (RH-77) Baseband Description and Troubleshooting Nokia Customer Care

Contents Page

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

Baseband and RF Architecture.................................................................................................................... 4

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

Power Up - Power Key............................................................................................................................. 7

Power Up - Charger ................................................................................................................................. 7

Power Up - RTC Alarm............................................................................................................................. 8

Power Off .......................................................................................................................................................8

Power Consumption and Operation Modes .........................................................................................8

Power Distribution ......................................................................................................................................9

Clock Distribution ......................................................................................................................................11

RFClk (19.2 MHz Analog)..................................................................................................................... 11

RFConvClk (19.2 MHz digital) ............................................................................................................ 13

CBUS Clk Interface ................................................................................................................................ 14

DBUS Clk Interface................................................................................................................................ 14

SleepCLK (Digital) .................................................................................................................................. 15

SleepCLK (Analog).................................................................................................................................. 15

Flash Programming Error Codes .............................................................................................................. 16

Charging Operation..................................................................................................................................... 18

Battery ..........................................................................................................................................................18

Charging Circuitry .....................................................................................................................................18

Charger Detection .....................................................................................................................................19

Charge Control ...........................................................................................................................................20

Audio .............................................................................................................................................................20

Display and Keyboard ...............................................................................................................................21

Flashlight.................................................................................................................................................. 21

Accessories ..................................................................................................................................................22

Charging................................................................................................................................................... 23

Pop-port Headset Detection.....................................................................................................

FBus Detection........................................................................................................................................ 24

Accessory Detection Through ACI..................................................................................................... 25

SIM CAR .......................................................................................................................................................26

Test Points...................................................................................................................................................... 28

Troubleshooting............................................................................................................................................ 30

Mobile Terminal is Dead ..........................................................................................................................31

Flash Programming Does Not Work .....................................................................................................32

Power Does Not Stay on or the Mobile Terminal is Jammed ........................................................34

Charger .........................................................................................................................................................36

Audio Faults ................................................................................................................................................37

Display Faults ..............................................................................................................................................41

Keypad Faults .............................................................................................................................................43

Flashlight .....................................................................................................................................................45

.......... 24

2118 (RH-77)

Nokia Customer Care Baseband Description and Troubleshooting

Introduction

The baseband module is a CDMA single-band engine based on the DCT4 architecture and consists of three ASICs: Universal Energy Management cost effective (UEMC), Universal Phone Processor (UPP8M4.2), and a 64 megabit FLASH.

The baseband architecture supports a power-saving function called sleep mode. Sleep mode shuts off the VCTCXO, which is used as the system clock source for both the RF and the baseband. During sleep mode, the system runs from a 32 kHz crystal and all the RF regulators (VR1A, VR1B, VR2, … VR7) are off. The sleep time is determined by network parameters. Sleep mode is entered when both the MCU and the DSP are in standby mode and the normal VCTCXO clock is switched off. The mobile terminal is waken up by a timer running from this 32 kHz clock supply. The period of the sleep/wake up cycle (slotted cycle) is 1.28N seconds, where N= 0, 1, 2, depending on the slot cycle index.

2118 supports standard Nokia 2-wire and 3-wire chargers (ACP-x and LCH-x). However, the 3-wire chargers are treated as 2-wire chargers. The PWM control signal for controlling the 3-wire charger is ignored. UEMC ASIC and EM SW control charging.

BL-5C Li-ion battery is used as main power source and has nominal capacity of 850 mAh.

2118 (RH-77) Baseband Description and Troubleshooting Nokia Customer Care

Baseband and RF Architecture

Charger

Bottom

Conn.

Sleep Clk

32 KHz

Audio

MBus

FBusRx

FBusT

SIM Reader

UEMC

VR1A VR1B

VR2 VR3

VR4 VR5 VR6 VR7

VBatt

Battery

VIO

VANA

V SIM

Vflash1

Vflash2

Dlight Klight

JTAG

DC/DC

VPPPRODTP

CBus

MBus

FBus

GenIO

Control

Flash

ExtBus

UPP

Core

N2302

Front

End

VCTCXO

19.2 MHz

System

Connector

V Bat

N700

VBatt

Figure 1: Power distribution

Bus

UHF

SYNTH

Flashlight

N601

V Bat

LCD/Key

2118 (RH-77)

Nokia Customer Care Baseband Description and Troubleshooting

Power Up and Reset

Power up and reset are controlled by the UEMC ASIC. The baseband can be powered up in the following ways:

• Pressing the Power button, which means grounding the PWRONX pin of the UEMC

• Connecting the charger to the charger input

• Initiating the RTC Alarm, when the RTC logic has been programmed to give an alarm

After receiving one of the above signals, the UEMC counts a 20 ms delay and then enters reset mode. The watchdog starts, and if the battery voltage is greater than Vcoff+, a 200 ms delay is started to allow references (etc.) to settle. After this delay elapses, the VFLASH1 regulator is enabled. Then, 500 us later, the VR3, VANA, VIO, and VCORE are enabled. Finally, the Power Up Reset (PURX) line is held low for 20 ms. This reset (PURX) is sent to the UPP. Resets are generated for the MCU and the DSP. During this reset phase, the UEMC forces the VCTCXO regulator on — regardless of the status of the sleep control input signal to the UEMC. The FLSRSTx from the UPP is used to reset the flash during power up and to put the flash in power down during sleep. All baseband regulators are switched on when the UEMC is powered on. The UEMC internal watchdogs are running during the UEMC reset state, with the longest watchdog time selected. If the watchdog expires, the UEMC returns to the power off state. The UEMC watchdogs are internally acknowledged at the rising edge of the PURX signal to always give the same watchdog response time to the MCU.

The following timing diagram represents the UEMC start-up sequence from reset to power-on mode.

2118 (RH-77) Baseband Description and Troubleshooting Nokia Customer Care

Figure 2: Power-on sequence and timing

2118 (RH-77)

Nokia Customer Care Baseband Description and Troubleshooting

Power Up - Power Key

When the power key is pressed, the UEMC enters the power-up sequence. Pressing the power key causes the PWRONX pin on the UEMC to be grounded. The UEMC PWRONX signal is not part of the keypad matrix. The power key is only connected to the UEMC. This means that when pressing the power key an interrupt is generated to the UPP that starts the MCU. The MCU then reads the UEMC interrupt register and notices that it is a PWRONX interrupt. The MCU reads the status of the PWRONX signal using the UEMC control bus (CBUS). If the PWRONX signal stays low for a certain time the MCU accepts this as a valid power-on state and continues with the SW initialization of the baseband. If the power key does not indicate a valid power-on situation, the MCU powers off the baseband.

Power Up - Charger

In order to be able to detect and start charging in cases where the main battery is fully discharged (empty) and hence UEMC has no supply (NO_SUPPLY or BACKUP mode of UEMC), charging is controlled by start-up charging circuitry.

Whenever the VBAT level is detected to be below the master reset threshold (V charging is controlled by START_UP charge circuitry. Connecting a charger forces the

Figure 3: Measured power-on sequence and timing

MSTR-

2118 (RH-77) Baseband Description and Troubleshooting Nokia Customer Care

VCHAR input to rise above the charger detection threshold (VCH start-up charging is initiated. The UEMC generates 100 mA constant output current from

the connected charger’s output voltage. The battery’s voltage rises at it charges, and when the VBAT voltage level is detected to be higher than master reset threshold limit (V

), the START_UP charge is terminated.

MSTR+

Monitoring the VBAT voltage level is done by charge control block (CHACON). A MSTRX=‘1’ output reset signal (internal to the UEMC) is given to the UEMC’s reset block when the VBAT>V

If the VBAT is detected to fall below V cancelled. It will restart if a new rising edge on VCHAR input is detected (VCHAR rising

above VCH

DET+

Power Up - RTC Alarm

If the mobile terminal is in power-off mode when the RTC alarm occurs, the wake-up procedure intiates. After the baseband is powered on, an interrupt is given to the MCU. When an RTC alarm occurs during active mode, the interrupt is generated to the MCU.

Power Off

and the UEMC enters into the reset sequence.

MSTR+

during start-up charging, charging is

MSTR

) and by detection,

DET+

The baseband switches to power-off mode if any of following occurs:

• Power key is pressed

• Battery voltage is too low (VBATT < 3.2 V)

• Watchdog timer register expires

The UEMC controls the power-down procedure.

Power Consumption and Operation Modes

In power-off mode, the power (VBAT) is supplied to the UEMC, vibra, LED, PA, and PA drivers. During this mode, the current consumption is approximately 35 uA.

In the sleep mode, both processors (MCU and DSP) are in stand-by mode. The mobile terminal enters sleep mode only when both processors make this request. When the SLEEPX signal is detected low by the UEMC, the mobile terminal enters sleep mode. The VIO and VFLASH1 regulators are put into low quiescent current mode, VCORE enters LDO mode, and the VANA and VFLASH2 regulators are disabled. All RF regulators are disabled during sleep mode. When the SLEEPX signal is detected high by the UEMC, the mobile terminal enters ACTIVE mode and all functions are activated.

Sleep mode is exited either by the expiration of a sleep clock counter in the UEMC or by some external interrupt (generated by a charger connection, key press, headset connection, etc.).

In sleep mode, the VCTCXO is shut down and the 32 kHz sleep clock oscillator is used as a reference clock for the baseband.

2118 (RH-77)

Nokia Customer Care Baseband Description and Troubleshooting

In ACTIVE mode, the mobile terminal is in normal operation, scanning for channels, listening to a base station, transmitting and processing information. There are several sub-states in the active mode depending on the mobile terminal present state of the mobile terminal, such as burst reception, burst transmission, if the DSP is working, etc.

In active mode, SW controls the UEMC RF regulators: VR1A and VR1B can be enabled or disabled. VSIM can be enabled or disabled and its output voltage can be programmed to be 1.8 V or 3.3 V. VR2 and VR4—VR7 can be enabled or disabled or forced into low quiescent current mode. VR3 is always enabled in active mode and disabled during Sleep mode and cannot be control by SW in the same way as the other regulators. VR3 will only turn off if both processors request to be in sleep mode.

CHARGING mode can be performed 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. This capacity value is related to the battery technology.

The battery voltage, temperature, size, and charging current are measured by the UEMC, and the charging software running in the UPP controls it.

The charging control circuitry (CHACON) inside the UEMC controls the charging current delivered from the charger to the battery and mobile terminal. The battery voltage rise is limited by turning the UEMC switch off when the battery voltage has reached 4.2 V. The charging current is monitored by measuring the voltage drop across a 220 mOhm resistor.

Power Distribution

In normal operation, the baseband is powered from the mobile terminal‘s battery. The battery consists of one Lithium-Ion cell capacity of 850 mAh and some safety and protection circuits to prevent harm to the battery.

The UEMC ASIC controls the power distribution to the whole mobile terminal through the BB and RF regulators excluding the power amplifier (PA), which has a continuous power rail directly from the battery. The battery feeds power directly to the following parts of the system:

•UEMC

•PA

•Vibra

•Display

• Keyboard lights

The heart of the power distribution to the mobile terminal is the power control block inside the UEMC. It includes all the voltage regulators and feeds the power to the whole system. The UEMC handles hardware power-up functions so the regulators are not powered and the power up reset (PURX) is not released if the battery voltage is less than 3 V.

2118 (RH-77) Baseband Description and Troubleshooting Nokia Customer Care

The 2118 baseband is powered from five different UEMC regulators (see Table 1).

Table 1: Baseband Regulators

Regulator

VCORE 300 1.35/1.05 Power up default 1.35 V and 1.05 V in Sleep Mode.

VIO 150 1.8 Enabled always except during power-off mode

VFLASH1 70 2.78 Enabled always except during power-off mode

VFLASH2 40 2.78 Enabled only when data cable is connected

VANA 80 2.78 Enabled only when the system is awake (Off during

VSIM 25 3.0 Enabled only when SIM card is used

Maximum Current (mA)

Vout (V) Notes

sleep and power off-modes)

Table 2 includes the UEMC regulators for the RF.

Table 2: RF Regulators

Regulator

VR1A 10 4.75 Enabled when cell transmitter is on

VR1B 10 4.75 Enabled when the transmitter is on

Maximum Current (mA)

Vout (V) Notes

VR2 100 2.78 Enabled when the transmitter is on

VR3 20 2.78 Enabled when SleepX is high

VR4 50 2.78 Enabled when the receiver is on

VR5 50 2.78 Enabled when the receiver is on

VR6 50 2.78 Enabled when the transmitter is on

VR7 45 2.78 Enabled when the receiver is on

The charge pump that is used by VR1A is constructed around the UEMC. The charge pump works with the CBUS (1.2 MHz) oscillator and gives a 4.75 V regulated output voltage to the RF.

2118 (RH-77)

Nokia Customer Care Baseband Description and Troubleshooting

Clock Distribution

RFClk (19.2 MHz Analog)

The main clock signal for the baseband is generated from the voltage and temperature controlled crystal oscillator VCTCXO (G500). This 19.2 MHz clock signal is generated at the RF and is fed to N700 pin 18 (TCXO_IN). N700 then converts the analog sine waveform to a digital waveform with a swing voltage of 0 tot 1.8 V and sends it to the UPP from pin 16 at N700 (19.2 Out) to the UPP pin M5 (RFCLK).

Figure 4: Waveform of the 19.2 MHz clock (VCTCXO) going to the N700 ASIC

2118 (RH-77) Baseband Description and Troubleshooting Nokia Customer Care

Figure 5 shows the RFCLK signal for the UPP.

Figure 5: Waveform of the 19.2 MHz Clk going to the UPP for N700 ASIC at C711

2118 (RH-77)

Nokia Customer Care Baseband Description and Troubleshooting

RFConvClk (19.2 MHz digital)

The UPP distributes the 19.2 MHz internal clock to the DSP and MCU, where the software multiplies this clock by seven for the DSP and by two for the MCU.

Figure 6: RFCovCLk waveform

2118 (RH-77) Baseband Description and Troubleshooting Nokia Customer Care

CBUS Clk Interface

A 1.2 MHz clock signal is used for CBUS, which is used by the MCU to transfer data between the UEMC and UPP.

DBUS Clk Interface

A 9.6 MHz clock signal is used for DBUS, which is used by the DSP to transfer data between the UEMC and UPP.

Figure 7: CBUS data transfer

Figure 8: Dbus data transferring

The system clock is stopped during sleep mode by disabling the VCTCXO power supply (VR3) from the UEMC regulator output by turning off the controlled output signal SleepX from the UPP.

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