LG C3100 User manual

Service Manual Model : C3100
Service Manual
C3100
P/N : MMBD0033001 Date : June, 2004 / Issue 1.0

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1. INTRODUCTION ................................... 2
1.1 Purpose ................................................ 2
1.2 Regulatory Information ......................... 2
1.3 Abbreviations ........................................ 4
2. PERFORMANCE .................................. 6
2.1 H/W Features ....................................... 6
2.2 Technical Specification ......................... 7
3. TECHNICAL BRIEF .......................... 11
3.1 Transceiver (SI4205, U401) ............... 11
3.2 Power Amplifier Module (RF3133, U400)
.. 16
3.3 13 MHz Clock ..................................... 17
3.4 Power Supplies for RF Circuits .......... 17
3.5 Digital Main Processor (AD6525, U100)
... 18
3.6 Analog Main Processor (AD6521, U101)
.. 23
3.7 Power Management IC (ADP3522, U301)
.27
3.8 Memory (U300) .................................. 28
3.9 LCD and LCD Backlight ..................... 28
3.10 Keypad Switches and Key Backlight
Illumination ......................................... 30
3.11 Microphone ......................................... 31
3.12 Dual Mode Speaker and MIDI IC ....... 32
3.13 Headset Jack Interface ....................... 32
4. TROUBLE SHOOTING .................... 35
4.1 RF Components ................................. 35
4.2 RX Trouble ......................................... 36
4.3 TX Trouble .......................................... 43
4.4 Power On Trouble .............................. 51
4.5 Charging Trouble ................................ 53
4.6 LCD Trouble ....................................... 55
4.7 Receiver Trouble ................................ 56
4.8 Speaker Trouble ................................. 57
4.9 MIC Trouble ........................................ 59
4.10 Vibrator Trouble .................................. 60
4.11 Key Backlight LED Trouble ................ 62
4.12 SIM Detect Trouble ............................ 63
4.13 Ear Jack Trouble ................................ 64
5. DISASSEMBLY INSTRUCTION .... 66
6.
DOWNLOAD AND CALIBRATION
.... 72
6.1 Download ........................................... 72
6.2 Calibration .......................................... 79
7. BLOCK DIAGRAM ............................ 82
8. CIRCUIT DIAGRAM .......................... 83
9. PCB LAYOUT ...................................... 89
10. ENGINEERING MODE .................. 91
10.1 BB Test [MENU 1] .......................... 91
10.2 RF Test [MENU 2] .......................... 93
10.3 MF Mode [MENU 3]......................... 93
10.4 Trace option [MENU 4]..................... 94
10.5 Call Timer [MENU 5] ...................... 94
10.6 Fact. Reset [MENU 6] .................... 94
10.7 S/W version [MENU 7] .................. 94
11. STAND ALONE TEST .................... 95
11.1 What’s the Standalone Test? .......... 95
11.2 Standalone Test Equipment Setup
...... 96
11.3 HW Test : Software for Standalone
Test Setup ...................................... 97
11.4 Tx Stand alone Test Setting ........... 98
11.5 Rx Stand alone Test Setting ........ 100
12. AUTO CALIBRATION .................. 102
12.1 Overview ...................................... 102
12.2 Equipment List ............................. 102
12.3 Equipment Setup .......................... 103
12.4 AGC for RX .................................. 104
12.5 APC for TX ................................... 104
12.6 ADC .............................................. 105
12.7 How to do calibration .................... 105
13. EXPLODED VIEW &
REPLACEMENT PART LIST ...... 107
13.1 Exploded View ............................ 107
13.2 REPLACEMENT PARTS ............ 109
Table Of Contents

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1. INTRODUCTION
1.1 Purpose
This manual provides the information necessary to repair, calibration, description and download
the features of C3100.
1.2 Regulatory Information
A. Security
Toll fraud, the unauthorized use of telecommunications system by an unauthorized part (for
example, persons other than your company’s employees, agents, subcontractors, or person
working on your company’s behalf) can result in substantial additional charges for your
telecommunications services. System users are responsible for the security of own system.
There may be risks of toll fraud associated with your telecommunications system. System users
are responsible for programming and configuring the equipment to prevent unauthorized use.
The manufacturer does not warrant that this product is immune from the above case but will
prevent unauthorized use of common-carrier telecommunication service of facilities accessed
through or connected to it. The manufacturer will not be responsible for any charges that are
resulted from such unauthorized use.
B. Incidence of Harm
If a telephone company determines that the equipment provided to customer is faulty and
possibly causing harm or interruption in service to the telephone network, it should disconnect
telephone service until repair can be done. A telephone company may temporarily disconnect
service as long as repair is not done.
C. Changes in Service
A local telephone company may make changes in its communications facilities or procedure.
If these changes could reasonably be expected to affect the use of this phone or compatibility
with the network, the telephone company is required to give advanced written notice to the user,
allowing the user to take appropriate steps to maintain telephone service.
D. Maintenance Limitations
Maintenance limitations on this model must be performed only by the manufacturer or its
authorized agent. Therefore, note that unauthorized alternations or repair may affect the
regulatory status of the system and may void any remaining warranty.
E. Notice of Radiated Emissions
This model complies with rules regarding radiation and radio frequency emission as defined by
local regulatory agencies. In accordance with these agencies, you may be required to provide
information such as the following to the end user.
1. INTRODUCTION

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F. Pictures
The pictures in this manual are for illustrative purposes only; your actual hardware may look
slightly different.
G. Interference and Attenuation
Phone may interfere with sensitive laboratory equipment, medical equipment, etc. Interference
from unsuppressed engines or electric motors may cause problems.
H. Electrostatic Sensitive Devices
ATTENTION
Boards, which contain Electrostatic Sensitive Device (ESD), are indicated by the sign.
Following information is ESD handling:
Service personnel should ground themselves by using a wrist strap when exchange system
boards.
When repairs are made to a system board, they should spread the floor with anti-static mat
which is also grounded.
Use a suitable, grounded soldering iron.
Keep sensitive parts in these protective packages until these are used.
When returning system boards or parts like EEPROM to the factory, use the protective
package as described.
1. INTRODUCTION

1. INTRODUCTION
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1.3 Abbreviations
For the purposes of this manual, following abbreviations apply:
APC Automatic Power Control
BB Baseband
BER Bit Error Rate
CC-CV Constant Current – Constant Voltage
DAC Digital to Analog Converter
DCS Digital Communication System
dBm dB relative to 1 milli watt
DSP Digital Signal Processing
ESD Electrostatic Discharge
FPCB Flexible Printed Circuit Board
GMSK Gaussian Minimum Shift Keying
GPIB General Purpose Interface Bus
GSM Global System for Mobile Communications
IPUI International Portable User Identity
IF Intermediate Frequency
LCD Liquid Crystal Display
LDO Low Drop Output
LED Light Emitting Diode
OPLL Offset Phase Locked Loop
PAM Power Amplifier Module
PCB Printed Circuit Board
PGA Programmable Gain Amplifier
PLL Phase Locked Loop
PSTN Public Switched Telephone Network
RF Radio Frequency
RLR Receiving Loudness Rating
RMS Root Mean Square
RTC Real Time Clock
SAW Surface Acoustic Wave

1. INTRODUCTION
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SIM Subscriber Identity Module
SLR Sending Loudness Rating
SRAM Static Random Access Memory
PSRAM Pseudo SRAM
STMR Side Tone Masking Rating
TA Travel Adapter
TDD Time Division Duplex
TDMA Time Division Multiple Access
UART Universal Asynchronous Receiver/Transmitter
VCO Voltage Controlled Oscillator
VCTCXO Voltage Control Temperature Compensated Crystal Oscillator
WAP Wireless Application Protocol

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2. PERFORMANCE
2.1 H/W Features
Item Feature Comment
Li-ion, 950 mAh
Standard Battery Size: 35.00 x 53.45 x 5.7mm
Weight: 30.00g
Under the minimum current consumption environment
Stand by Current (such as paging period 9), the level of standby current
is below 4mA.
Talk time Up to 3 hours (GSM TX Level 7)
Stand by time Up to 200 hours (Paging Period: 9, RSSI: -85 dBm)
Charging time 3.5 hours
RX Sensitivity GSM, EGSM: –105dBm, DCS: –105dBm
TX output power GSM, EGSM: 32dBm (Level 5),
DCS: 29dBm (Level 0)
GPRS compatibility Class 10
SIM card type 3V Small
Display 128 x 128 pixel 65K Color
Hard icons. Key Pad;
Status Indicator 0 ~ 9, #, *, Up/Down/Left/Right Navigation Key,
OK key, Confirm key, Clear Key, Back Key,
Send Key, END/PWR Key
ANT Internal
EAR Phone Jack Yes
PC Synchronization Yes
Speech coding EFR/FR/HR
Data and Fax Yes
Vibrator Yes
Loud Speaker Yes
Voice Recording Yes
C-Mike Yes
Receiver Yes
Travel Adapter Yes
Options Hands-free kit, CLA, Data Kit
2. PERFORMANCE

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2. PERFORMANCE
2.2 Technical Specification
Item Description Specification
GSM
TX: 890 + n x 0.2 MHz
RX: 935 + n x 0.2 MHz (n=1~124)
EGSM
1 Frequency Band TX: 890 + (n-1024) x 0.2 MHz
RX: 935 + (n-1024) x 0.2 MHz (n=975~1024)
DCS
TX: 1710 + (n-512) x 0.2 MHz
RX: 1805 + (n-512) x 0.2 MHz (n=512~885)
2 Phase Error RMS < 5 degrees
Peak < 20 degrees
3 Frequency Error < 0.1 ppm
GSM, EGSM
Level Power Toler. Level Power Toler.
5 33 dBm 2dB 13 17 dBm 3dB
6 31 dBm 3dB 14 15 dBm 3dB
7 29 dBm 3dB 15 13 dBm 3dB
8 27 dBm 3dB 16 11 dBm 5dB
9 25 dBm 3dB 17 9 dBm 5dB
10 23 dBm 3dB 18 7 dBm 5dB
11 21 dBm 3dB 19 5 dBm 5dB
12 19 dBm 3dB
4 Power Level DCS
Level Power Toler. Level Power Toler.
0 30 dBm 2dB 8 14 dBm 3dB
1 28 dBm 3dB 9 12 dBm 4dB
2 26 dBm 3dB 10 10 dBm 4dB
3 24 dBm 3dB 11 8 dBm 4dB
4 22 dBm 3dB 12 6 dBm 4dB
5 20 dBm 3dB 13 4 dBm 4dB
6 18 dBm 3dB 14 2 dBm 5dB
7 16 dBm 3dB 15 0 dBm 5dB

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Item Description Specification
GSM, EGSM
Offset from Carrier (kHz). Max. dBc
100 +0.5
200 –30
250 –33
400 –60
600~ <1,200 –60
1,200~ <1,800 –60
1,800~ <3,000 –63
3,000~ <6,000 –65
5 Output RF Spectrum 6,000 –71
(due to modulation) DCS
Offset from Carrier (kHz). Max. dBc
100 +0.5
200 –30
250 –33
400 –60
600~ <1,200 –60
1,200~ <1,800 –60
1,800~ <3,000 –65
3,000~ <6,000 –65
6,000 –73
GSM, EGSM
Offset from Carrier (kHz). Max. dBm
400 –19
600 –21
1,200 –21
6 Output RF Spectrum 1,800 –24
(due to switching GSM
transient)
Offset from Carrier (kHz). Max. dBm
400 –22
600 –24
1,200 –24
1,800 –27
7 Spurious Emissions Conduction, Radiation
2. PERFORMANCE

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2. PERFORMANCE
Item Description Specification
GSM, EGSM
8 Bit Error Rate BER (Class II) < 2.439% @–102 dBm
DCS
BER (Class II) < 2.439% @–100 dBm
9 RX Level Report Accuracy 3 dB
10 SLR 8 3 dB
Frequency (Hz) Max.(dB) Min.(dB)
100 –12 –
200 0 –
300 0 –12
11 Sending Response 1,000 0 –6
2,000 4 –6
3,000 4 –6
3,400 4 –9
4,000 0 –
12 RLR 2 3 dB
Frequency (Hz) Max. (dB) Min. (dB)
100 –12 –
200 0 –
300 2 –7
500 ❈–5
13 Receiving Response 1,000 0 –5
3,000 2 –5
3,400 2 –10
4,000 2
* Mean that Adopt a straight line in between 300 Hz
and 1,000 Hz to be Max. level in the range.
14 STMR 13 5 dB
15 Stability Margin > 6 dB
dB to ARL (dB) Level Ratio (dB)
–35 17.5
–30 22.5
16 Sending Distortion –20 30.7
–10 33.3
0 33.7
7 31.7
10 25.5
17 Side tone Distortion Three stage distortion < 10%
18 System frequency ≤2.5 ppm
(13 MHz) tolerance
19 32.768KHz tolerance ≤30 ppm

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Item Description Specification
At least 80 dB under below conditions:
20 Ringer Volume 1. Ringer set as ringer.
2. Test distance set as 50 cm.
21 Charge Current CC Charge : < 500 mA
Trickle Charge : < 60 mA
Antenna Bar Number Power
5 –85 dBm ~
4 –90 dBm ~ –86 dBm
22 Antenna Display 3 –95 dBm ~ –91 dBm
2 –100 dBm ~ –96 dBm
1 –105 dBm ~ –101 dBm
0 ~ –105 dBm
Battery Bar Number Voltage
0 ~ 3.62V
23 Battery Indicator 1 3.62 ~ 3.73V
2 3.73 ~ 3.82V
3 3.82V ~
24 Low Voltage Warning 3.5 0.03V (Standby)
3.62 0.03V (Call)
25 Forced shut down 3.35 0.03V
Voltage
1 Li-ion Battery
26 Battery Type Standard Voltage = 3.7V
Battery full charge voltage = 4.2V
Capacity : 950mAh
Switching-mode charger
27 Travel Charger Input : 100 ~ 240V, 50/60 Hz
Output : 5.2V, 800 mA
2. PERFORMANCE

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3. TECHNICAL BRIEF
3.1 Transceiver (SI4205, U401)
The RF parts consist of a transmitter part, a receiver part, a frequency synthesizer part,
a voltage supply part, and a VCTCXO part.
The Aero I transceiver is the integrated RF front end for multi-band GSM/GPRS digital cellular
handsets and wireless data modems. The integrated solution eliminates the IF SAW filter,
external low noise amplifier (LNAs) for three bands, transmit and RF voltage controlled oscillator
VCO modules, and other discrete components found in conventional designs.
Functional Description
Figure 3-1. Block Diagram of SI4205
ANTENNA SWITSH
TCXO
3. TECHNICAL BRIEF

(1) Receiver part
The Aero I transceiver uses a low-IF receiver architecture which allows for the on chip
integration of the channel selection filters, eliminating the external RF image reject filters and the
IF SAW filter required in conventional superheterodyne architectures.
A. RF front end
RF front end consists of Antenna Switch (FL400), two SAW Filters (FL401, FL402) and dual
band LNAs integrated in transceiver (U401).
The Received RF signals (GSM 925MHz ~ 960MHz, DCS 1805MHz ~ 1880MHz) are fed into
the antenna or Mobile switch.
The Antenna Switch (FL400) is used to control the Rx and Tx paths. And, the input signals
VC1 and VC2 of a FL400 are directly connected to baseband controller to switch either
Tx or Rx path on.
The logic and current is given below Table 3-1.
Table 3-1. The Logic and current
Three differential-input LNAs are integrated in SI4205. The GSM input supports the GSM 850
(869-849 MHz) or E-GSM 900 (925-960MHz) bands. The DCS input supports the DCS 1800
(1805-1880 MHz) band. The PCS input supports the PCS 1900 (1930-1990 MHz) band.
The LNA inputs are matched to the 150Ωbalanced output SAW filters through external LC
matching networks. The LNA gain is controlled with the LNAG[1:0] and LNAC[1:0] bits in
register 05h (Figure 3-2).
VC1 VC2 Current
DCS TX 0V 2.5 ~ 3.0V 10.0 mA max
GSM TX 2.5 ~ 3.0V 0V 10.0 mA max
GSM/DCS RX 0V 0V < 0.1 mA
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3. TECHNICAL BRIEF

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3. TECHNICAL BRIEF
Figure 3-2. Block Diagram of Receiver part of SI4205
B. Intermediate frequency (IF) and Demodulation
A quadrature image-reject mixer downconverts the RF signal to a 100KHz intermediate
frequency (IF) with the RFLO from the frequency synthesizer. The RFLO frequency is
between 1737.8 to 1989.9 MHz, and is internally divided by 2 for GSM 850 and E-GSM 900
modes. The mixer output is amplified with an analog programmable gain amplifier (PGA),
which is controlled with the AGAIN[2:0] bits in register 05h (Figure 3-2). The quadrature IF
signal is digitized with high resolution A/D converters (ADCs).
The ADC output is downconverted to baseband with a digital 100KHz quadrature LO signal.
Digital decimation and IIR filters perform channel selection to remove blocking and reference
interference signals. The selectivity setting (CSEL=0) or a low selectivity setting (CSEL=1).
The low selectivity filter has a flatter group channelization filter is in the baseband chip. After
channel selection, the digital output is scaled with a digital PGA, which is controlled with the
DGAIN [5:0] bits in register 05h.
The amplified digital output signal go through with DACs that drive a differential analog signal
onto the RXIP,RXIN,RXQP and RXQN pins to interface to standard analog ADC input
baseband ICs. No special processing is required in the baseband for offset compensation or
extended dynamic range.
Compared to a direct-conversion architecture, the low-IF architecture has a much greater
degree of immunity to dc offsets that can arise from RF local oscillator (RFLO) self-mixing,
2nd order distortion of blockers, and device 1/f noise.

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(2) Transmitter part
The transmit (Tx) section consists of an I/Q baseband upconverter, and offset phase-locked
loop (OPLL) and two output buffers that can drive external power amplifiers (PA), one for the
GSM 850 (824-849 MHz) and E-GSM 900 (880-915 MHz) bands and one for the DCS 1800
(1710-1785 MHz) and PCS 1900 (1850-1910MHz) bands.
Figure 3-3. Block Diagram of Transmitter part of SI4205
A. IF Modulator
The baseband converter (BBC) within the GSM chipset generates I and Q baseband signals
for the Transmit vector modulator. The modulator provides more than 40dBc of carrier and
unwanted sideband rejection and produces a GMSK modulated signal. The baseband
software is able to cancel out differential DC offsets in the I/Q baseband signals caused by
imperfections in the D/A converters.
The Tx-Modulator implements a quadrature modulator. A quadrature mixer upconverts the
differential in-phase (TXIP, TXIN) and quadrature (TXQP, TXQN) signals with the IFLO to
generate a SSB IF signal that is filtered and used as the reference input to the OPLL.
The IFLO frequency is generated between 766 and 896 MHz and internally divided by 2 to
generate the quadrature LO signals for the quadrature modulator, resulting in an IF between
383 and 448 MHz. For the E-GSM 900 band, two different IFLO frequencies are required for
spur management. Therefore, the IF PLL must be programmed per channel in the E-GSM
900 band.
B. OPLL
The OPLL consists of a feedback mixer, a phase detector, a loop filter, and a fully integrated
TXVCO. The TXVCO is centered between the DCS 1800 and PCS 1900 bands, and its
output is divided by 2 for the GSM 850 and E-GSM 900 bands. The RFLO frequency is
generated between 1272 and 1483 MHz. To allow a single VCO to be used for the RFLO,
high-side injection is used for the GSM 850 and E-GSM 900 bands, and low-side injection is
used for the DCS 1800 and PCS 1900 bands. The I and Q signals are automatically swapped
when switching bands. Additionally, the SWAP bit in register 03h can be used to manually
exchange the I and Q signals. Low-pass filters before the OPLL phase detector reduce the
harmonic content of the quadrature modulator and feedback mixer outputs. The cutoff
frequency of the filters is programmable with the FIF[3:0] bits in register 04h (Figure 3-3), and
should be set to the recommended settings detailed in the register description.
3. TECHNICAL BRIEF
÷2
BBG[1:0]
FIF[3:0]
TXBAND[1:0]
PDIB
PDRB
SWAP TXIP
TXIN
I
Q
TXQP
TXQN
÷1,2
REG
RFOG
RFOD
REG

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3. TECHNICAL BRIEF
(3) Frequency Synthesizer
Figure 3-4. Block Diagram of Frequency Synthesizer part of SI4205
The Aero I transceiver integrates two complete PLLs including VCOs, varactors, resonators,
loop filters, reference and VCO dividers, and phase detectors. The RF PLL uses two
multiplexed VCOs. The RF1 VCO is used for receive mode, and the RF2 VCO is used for
transmit mode. The IF PLL is used only during transmit mode. All VCO tuning inductors are
also integrated. The IF and RF output frequencies are set by programming the N-Divider
registers, NRF1, NRF2 and NIF. Programming the N-Divider register for either RF1 or RF2
automatically selects the proper VCO. The output frequency of each PLL is as follows :
The DIV2 bit in register 31h controls a programmable divider at the XIN pin to allow either a
13 or 26 MHz reference frequency. For receive mode, the RF1 PLL phase detector update
rate ( ) should be programmed = 100 kHz for DCS 1800 or PCS 1900 bands, and = 200
kHz for GSM 850 and E-GSM 900 bands. For transmit mode, the RF2 and IF PLL phase
detector update rates are always =200 kHz.

3.2 Power Amplifier Module (RF3133, U400)
The RF3133 is a high-power, high-efficiency power amplifier module with integrated power
control. The device is self-contained with 50Ωinput and output terminals. The power control
function is also incorporated, eliminating the need for directional couplers, detector diodes,
power control ASICs and other power control circuitry; this allows the module to be driven
directly from the DAC output.
The device is designed for use as the final RF amplifier in GSM 850, E-GSM 900, DCS and PCS
handheld digital cellular equipment and other applications in the 824-849 MHz, 880-915 MHz,
1710-1785 MHz, and 1850-1910 MHz bands.
On-board power control provides over 37 dB of control range with an analog voltage input
(TX_RAMP); and, power down with a logic “low”for standby operation (TX_ENABLE).
External control (BAND_SELECT) is used to select the GSM or DCS band with a logic high or
low. A logic low enables the GSM band whereas a logic high enables the DCS band.
Figure 3-5. Functional Block Diagram of RF3133
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1DSC/PCS IN
2
3
4
5
6
7
BAND SELECT
TX ENABLE
VBATT
VREG
VRAMP
GSM IN
DSC/PCS OUT
VCC2VCC2
VCC OUT
GSM OUT
11
8
12
10
9
3. TECHNICAL BRIEF

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3. TECHNICAL BRIEF
3.3 13 MHz Clock
The 13 MHz clock (X400) consists of a TCXO (Temperature Compensated Crystal Oscillator)
which oscillates at a frequency of 13 MHz. It is used within the Si4205, analog base band
chipset (U101, AD6521), digital base band chipset (U102, AD6525), and MIDI (U200) chipset.
Figure 3-6. VCTCXO circuit diagram
3.4 Power Supplies for RF Circuits
Two regulators are used for RF circuits. One is MIC5255 (U402), and the other is one port of
ADP3522 (U301).
MIC5255 (U402) supplies power to transceiver (SI4205, U401).
One port of ADP3522 supplies power to VCTCXO (X400).
Main power (VBAT) from battery is used for PAM (RF3133, U400) because PAM requires high
power.
Table 3-2. Power suppliers for RF circuits.
Figure 3-7. U402 circuit diagram
(1608)
100
R415
2V75_VTCXO
C435
2.2u
R414
15KC432
X400
OUT CTL
VCC GND
1
2
3
4
13MHz
1000p
AFC
Supplier Voltage Powers Enabled signal
U402 2.85V U401 RF_EN
U301 2.75V X400
Battery 3.4~4.2V U400
R418 NA
R419 0
0.01uC437
10u
C438
IN
5OUT
U402
MIC5255-2.85BM5
4BYP EN 3
GND 2
1
VBAT
VRF
10u
C436 RF_EN
CLKON

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3.5 Digital Main Processor (AD6525, U100)
(1) Architecture Overview
Figure 3-8. Block Diagram of the AD6525 Internal Architecture
The internal architecture of AD6525 is shown in Figure 3-8. AD6525 regroups three main
subsystems connected together through a dynamic and flexible communication by network.
It also includes onboard system RAM (SRAM) and interfaces with external Flash Memory,
Baseband converter functions, and terminal functions like MMI, SIM and Universal System
Connector (USC).
The Digital Signal Processing (DSP) subsystem primarily hosts all the speech processing,
channel equalization and channel codec functions. The code used to implement such functions
can be stored in external Flash Memory and dynamically downloaded on demand into the DSP’s
program RAM and Instruction Cache.
3. TECHNICAL BRIEF
AD6525
AD6525
(VBC)
DSF
SRAM FLASH
MMI
USC
MUC
Peripheral
RF-Control
Subsystem
Subsystem
Subsystem (ARM7TDMI®)
DMA and BUS
ARBITRARION
Serial Link
DSP BUS
RBUS
EBUS
PBUS
SBUS

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3. TECHNICAL BRIEF
The microcontroller subsystem supports all the GSM terminal software, including the layer 1, 2
and 3 of the GSM protocol stack, the MMI, and applications software such as data services, test
and maintenance. It is tightly associated with on-chip system SRAM and also includes boot
ROM memory with a small dedicated routine to facilitate the initialization of the external Flash
Memory via code download using the on-chip serial interface to the external Flash Memory
interface.
The peripheral subsystem is composed of system peripherals such as interrupt controller, real
time clock, watch dog timer, power management and a timing and control module. It also
includes peripheral interfaces to the terminal functions: keyboard, battery supervision, radio and
display. Both the DSP and the MCU can access the peripheral subsystem via the peripheral bus
(PBUS).
For program and data storage, both the MCU subsystem and the DSP subsystem can access
the on chip system SRAM and external memory such as Flash Memory. The access to the
SRAM module is made through the RAM Bus (RBUS) under the control of the bus arbitration
logic. Similarly, access to the Flash Memory is through the parallel External Bus (EBUS).