DA9191EB.006
June 30,1997
MAS9191EB
EVALUATION BOARD FOR CELLULAR BASEBAND ICs
•
Audio/Data Processor and all necessary external components
•
Battery Management IC and battery protection/charging circuit
•
VCTCXO with DAC voltage control
•
uP with evaluation software
DESCRIPTION
The Cellular Baseband evaluation board includes
MAS9191A (Audio/Data Processor), MAS9129
(Battery Management) and MS8323 (VCTCXO) ICs
with all needed external components and software.
The two regulators of MAS9129 provide all the power
for the board. The board has BNC connectors for
typical MAS9191A interfaces. By using customised
software and external RF parts the complete
evaluation of an AMPS/ ETACS/ NAMPS phone can
be performed. A general purpose micro controller is
used to control the MAS9191A internal registers
through a serial bus interface. For the micro controller
there is 32kB SRAM, 64kB FLASH, an LCD, a keypad
and an RS-232-C interface for software downloading
to SRAM or FLASH. There is also a direct interface to
the MAS9191A serial bus allowing an external
controller to be used.
FEATURES
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Fully operational system (only NiCd/NiMH battery
or power supply needed)
Connectors to Rx,Tx,microphone, ear piece, etc.
Several test points for audio block
Battery charger input (9.0VDC/265mA)
Micro controller with 32kB SRAM, 64kB FLASH
Keyboard and 2-line/16-character LCD
RS-232-C interface for software downloading
External micro controller connector
3.4 - 9.0 NiCd/NiMH battery input or power supply
MEASUREMENTS
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Regulator voltage and current
Receive and transmit frequency responses
Send and receive messages
Microphone and Rx audio levels
SAT detection and generation
Signalling Tone level
DTMF detection and generation
Gain control levels
Expander and compressor functionality
VCTCXO output signal
BLOCK DIAGRAM
ON/OFF
SWITCH
RX
MAS9129
LDO2
3.0V/50mA
MAS9191A
MIC
BATTERY
INPUT
(3.4 -9.0 VDC)
BUZZER
BATTERY
MANAGEMENT
BATTERY
CHARGER
(9.0 VDC/265mA)
XRESET
WATCHDOG
MICRO
CONTROLLER
EAR PIECE
SERIAL
INTERFACE
TEST
POINTS
AUDIO/DATA
PROCESSOR
LDO1
3.0V/100mA
DAC
TX
LCD DISPLAY
Vcont
MS8323
OSC
OUT
VCTCXO
KEYPAD
SRAM
32kB
FLASH
64kB
I/O
PORT
RS232C
RxD DTR TxD
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DA9191EB.006
June 30,1997
SYSTEM REQUIREMENTS
For the complete evaluation of MAS9191A, MAS9129 and MS8323 ICs the following equipment is needed:
•
Cellular Baseband Evaluation Board
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NiCd/NiMH Battery or DC power supply (3.4 to 9.0 VDC)
•
Battery charger (9.0VDC/265mA)
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Radio test system (e.g. Marconi 2965)
•
RF parts for AMPS/TACS/NAMPS cellular phone or a radio test system with an IF interface
•
PC with RS-232-C interface with serial cable (optional)
START UP
Connect the supply voltage or a battery to plus and
minus battery terminals. Turn on switch S1 to power
up the board. The power consumption of the
MAS9129 regulators can be measured by inserting an
ammeter between the pins at CM1 and CM2. After
powering up the system, the installed evaluation
software sets up and the evaluation board is now
ready for use. The power down modes of MAS9191A
are controlled by register 07
HEX
. The default values are
set by entering Register Write. See the
Register write
function in the next section. Rough testing of the
microphone, earphone, and buzzer interfaces can be
done with the MAS9191A internal loop back modes.
For more detailed evaluation, a radio test set is
needed. The board is assembled so that the micro
controller will operate at 8.0 MHz. The micro controller
can also be operated at 4.8 MHz by inserting jumper
P6 and disconnecting parts X2, R23, C50 and C51.
Current consumption of MAS9191A is measured at
jumper CM3.
EVALUATION SOFTWARE
The evaluation software has the following features:
- write function for changing the values of the MAS9191A registers
- read function for reading the values of the MAS9191A status registers
- message send
- message receive
A keypad serves as the software interface.
The key definitions are as follows:
- BACKWARD = 4
- TOGGLE
=5
- FORWARD = 6
- EXIT
=*
- ENTER
=#
- UP
=2
- DOWN
=8
After a reset the internal registers of the MAS9191A
are set to zero and the program returns to the main
menu, which will display the following message on the
LCD:
MAS9191EB
Press # for HELP
MAIN MENU
HELP
Register
Write
Register
Read
Message
Send
Message
Receive
Display
help
Select Register
or
Set Defaults
Select
Register
Select Message
or
Send Message
Receive
Message
Edit
Value
Read
Value
Edit
Message
Send
Messages
Program flow diagram
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DA9191EB.006
June 30,1997
EVALUATION SOFTWARE
x
Help
Pressing “#" will display instructions for the keys
shown on the LCD. Press EXIT to return to the main
menu.
x
Main menu
The FORWARD and BACKWARD keys will select
“register read”, “register write”, “message send” or
“message read”. The given function is executed by
pressing ENTER.
x
Register write
When entering this function the register address will
be shown at the top right. After entering the write
function, pressing “#' will automatically set the default
values (gain controls at nominal levels and necessary
switches in proper positions) to measure the transmit
and receive frequency responses. The register
address can be changed with the FORWARD and
BACKWARD keys. The lower line will show the
current contents of the register. Press EXIT to return
to the main menu. The ENTER key will remove the
brackets around the register address and the cursor
will move to the first nibble of the hex byte on the
lower line. The UP and DOWN keys will increment or
decrement the nibble. If the value of the register has
been changed there will be an asterisk next to the
register address. The FORWARD and BACKWARD
keys will move the cursor left and right, respectively.
When the cursor points to a bit of a register the
TOGGLE key will change the value of the bit. After a
bit has been edited the top line will display the function
of the bit. The ENTER key will write any new values to
the MAS9191A. Press EXIT to exit from the editing
mode. If the function is terminated without writing any
new values, the previous values are retained.
x
Register read
This function is quite similar to the register write
function. The register address is selected with
FORWARD and BACKWARD keys from the main
menu. The register can be read with the ENTER key.
Pressing the ENTER key a second time will update
the contents of the status register. The FORWARD
and BACKWARD keys will move the cursor and
display the function of each bit. Return to the top line
or to the main menu with the EXIT key.
x
Message receive
This function waits for 10 messages to be received.
When the messages are received they can be
examined with the FORWARD and BACKWARD
keys. The function can be terminated with the EXIT
key. An >N= in the upper right hand corner indicates
NAMPS mode.
x
Message send
In this function six messages can be entered. First the
desired message number must be chosen with the
FORWARD and BACKWARD keys. Then the ENTER
key will advance to the edit mode. With the
FORWARD and BACKWARD keys the nibbles of
each byte can be chosen and the value incremented
or decremented with the UP and DOWN keys. The
ENTER key will store the message into memory. The
EXIT key will move the cursor to the upper row. After
all messages are edited the LCD reads "SEND
MESSAGES". The ENTER key will move the cursor to
the lower row and the FORWARD and BACKWARD
keys will choose the message. The TOGGLE key will
alternate between the plus and minus signs. The plus
sign indicates that the message will be transmitted.
When all messages are chosen the ENTER key will
start the transmission, and may be done repeatedly.
The transmission can be terminated with the EXIT
key. An >N= in the upper right hand corner indicates
NAMPS mode.
x
Micro Controller and Interfaces
The 68HC11 micro controller can be reset with the
reset button, with DTR or by switching power off and
on. In the last case the voltage regulator internal reset
circuit will perform the reset. When the MOD jumper is
open the controller executes the software from the
FLASH ROM. When the jumper is closed the
controller enters the boot-strap mode after reset. In
this mode the software which contains the hl.exe
program can be loaded into the FLASH ROM or
SRAM through the RS-232-C interface. The syntax of
the software is:
el [-p<X>] <filename>
Where X is the serial port number: 1 for COM1 and 2
for COM2 and the file name is the same as the
S-record file without the extension. For downloading
the serial cable with the following connections are
needed:
PC
MAS9191A
2 ----- 2
3 ----- 3
7 ----- 7
20 ----- 20
More information about the 68HC11 is available from
the reference manual.
P9 contains six inputs to the micro controller port PE.
These inputs can be used as digital inputs or as
analog inputs for the A/D-converter.
When the micro controller is writing to address
0x1FFC and 0x1FFD the data is also written to the
LCD command register. Write cycles to memory
address 0x1FFD also change the state of the port at
0x1FFE. The port has eight outputs, ground and
supply voltage. The maximum load for the power
supply pin is 20 mA when operating at 3V. Keypad
interface is done with port PA. Pins PA0, PA1 and
PA2 are inputs from the 4x3 keypad and pins
PA3-PA6 are outputs to the matrix. PA7 is the output
pulse for MAS9129 watchdog circuit. All PA outputs
are driven with the external buffer IC3.
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DA9191EB.006
June 30,1997
FUNCTIONS
x
Battery Charging
If a battery is used to power MAS9129, the battery
may be charged by connecting the battery charger to
the charger input. The battery charging circuit
monitors the battery voltage level. When a negative
slope in the charging curve is detected, the charging is
stopped. The battery will be charged to 1 volt above
the nominal battery voltage level. The current into
MAS9129 can be monitored by jumper CM4.
x
MAS9129 Regulators
The voltage and current levels of the MAS9129
regulators can be measured at test points CM1 and
CM2. Remove the jumper and insert an ammeter to
monitor the current values. Regulator 2 is enabled by
jumper J2.
x
Microphone Interface
On the evaluation board there are three possibilities
for testing the microphone amplifier interface. The first
way is with an on-board microphone interface, which
may not be used in normal mode, but exhibits one way
of implementing an interface to a microphone by using
an external anti-aliasing filter. This microphone uses a
DC voltage from a basic voltage divider. The diagram
for this interface can be found in the schematic
section. Another possibility is to use external
microphone circuitry with the MAS9191A microphone
amplifier using connector J1. This is done by removing
the jumpers and connecting the microphone signal to
pin 2 and the feedback signal to pin 1. The third
possibility is to use the external microphone input
EXTMIC. The electrical characteristics of the EXTMIC
and MIC pins are found from the MAS9191A data
sheet.
x
Earphone Interface
The BNC-type and the header type connectors are
assembled for differential type earphone output. An
external earphone is supplied with the evaluation
board. The board is capable of driving this earphone
as well as other models directly at a 3V operation
voltage. Use the BNC connector EXTEARP for
external earphones. Detailed electrical descriptions of
these interfaces are found from the MAS9191A data
sheet.
x
Buzzer Interface
The buzzer is driven by transistor Q1. The model of
Q1 and the value of resistors R9 and R10 will affect
the levels of the buzzer tone significantly. To test an
external buzzer, connect it to the buzzer input pin.
x
Side Tone Circuit
The source of the side tone is recommended to be
taken from MICOUT of the MAS9191A located at pin
T2. The level of the side tone is controlled by the
external circuitry shown in the schematic section. The
level and the frequency response of the side tone can
be controlled by changing the values of components
R11, R12,C43 and C44.
x
RX and TX Interfaces
Two BNC connectors allow easy interface to RF
sections or to a radio test system. The transmit audio
signal as well as DTMF, ST, SAT and send messages
may be monitored at the Tx connector. The receive
audio signal as well as SAT and receive messages
are measured by applying the signals to the RX
connector. There are 22nF DC blocking capacitors on
both interfaces. The electrical characteristics can be
found from the MAS9191A data sheet.
x
Microphone and Rx Audio Level Measurement
The two internal operational amplifiers of the
MAS9191A are used to measure audio levels. The
level measurement is done with the circuit shown in
the schematic section. The level detection output is
monitored by the micro controller A/D converter. To
examine the operation of the level detector, measure
test points T6 and T7.
x
Test Points
There are seven test points along the Rx and Tx audio
section. These test points can be used to measure
gain control levels and the performance of the
compressor, expander, limiter and all filters. The pin
description section defines all test points.
x
CTRL Interface
The CTRL connector consists of the control signal
TXCTRL for the transmitter and two test indicators
BUSY and TXON. TXCTRL is an open collector output
and is low only when a transmission collision occurs.
After a collision TXCTRL goes to a high impedance
state and the TX block of the MAS9191A is reset with
TXRST.
x
Three 8-bit DAC Outputs
The DAC connector contains a direct interface to the
three MAS9191A internal 8-bit DACs.
x
MAS9191A Serial Bus Interface
The five row jumper for the MAS9191A serial bus to
the micro controller is normally closed. Remove the
jumpers for external control. The STB, SCL, SRXD,
STXD and XINT signals are located at pins 1, 2, 3, 4
and 5 respectively.
x
MS8323 Output Frequency
The output frequency of the VCTCXO can be
measured from test pin OSCOUT. The DAC1 output
from MAS9191A is the voltage control for the
VCTCXO which adjusts the output frequency. Jumper
J3 connects DAC1 to V
CONT
. The current consumption
of the VCTCXO can be measured through jumper
CM5.
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DA9191EB.006
June 30,1997
CONNECTOR DESCRIPTION
Connector name
Battery
Pin
Function
NiCd Battery or external DC power supply capable of driving at least 200 mA current is
connected to battery input.
B+
B-
Positive supply voltage from 3.4 V to 9.0V DC.
Ground.
S1
CM1
ON/OFF power switch for MAS9129 voltage regulators.
This jumper is normally closed, but can be opened to use an external current meter to
measure the power consumption of the digital section.
1
Regulator 1 output.
2
VDD input.
This jumper is normally closed, but can be opened to use an external current meter to
measure the power consumption of the analog section.
1
Regulator 2 output.
2
VDD input.
Microphone input.
Ground.
Microphone amplifier feedback signal. Connect to pin 3 to use the mounted
microphone. Otherwise, connect the external microphone circuit feedback
signal to this pin.
Microphone amplifier input. Connect this to pin 4 to use the mounted
microphone. Otherwise, connect the external microphone output signal to this
pin.
Feedback signal input for the assembled microphone circuit.
Microphone output signal for the assembled microphone circuit.
The microphone is normally connected to this connector. See the microphone function.
1
2
CM2
MIC
J1
The internal/external microphone select switches.
1
2
3
4
J2
EXTMIC
Use jumper to enable regulator 2.
BNC-type connector for external microphone source.
1
2
External microphone input.
Ground.
T2
T3
T4
T5
CM3
CM4
CM5
MICOUT signal is the output from the section which contains the following blocks: Filter F8,
Gain Control GC3 and Filter F9. The source for the signal is either from SGND, Microphone
amplifier A6, EXTMIC input or from DTMF generator.
COUT is the compressor output signal. The compressor and all the blocks before T2 can be
measured by using this test point.
LPFIN test point can be used as an output to measure gain controls GC4 and GC5, the filter
F10 and all the blocks before T3.
TAUDOUT is the output from the TX audio block.
1
2
1
2
1
2
VDD from regulator 2.
MASVDD. Power input for MAS9191A. Current measurement point.
Battery and charging voltage output.
Power input for MAS9129. Current measurement point.
VDD from regulator 2.
Power input for MS8323. Current measurement point.
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