Motorola Cm Radio Controlheads Manual

							Commercial SeriesCM Radios
Controlhead
Service Information
Issu e:  December  2 003 
						

							ii
Computer Software Copyrights
The Motorola products described in this manual may include copyrighted Motorola computer programs stored 
in semiconductor memories or other media. Laws in the United States and other countries preserve for 
Motorola certain exclusive rights for copyrighted computer programs, including the exclusive right to copy or 
reproduce in any form, the copyrighted computer program. Accordingly, any copyrighted Motorola computer 
programs contained in the Motorola products described in this manual may not be copied or reproduced in 
any manner without the express written permission of Motorola. Furthermore, the purchase of Motorola 
products shall not be deemed to grant, either directly or by implication, estoppel or otherwise, any license 
under the copyrights, patents or patent applications of Motorola, except for the normal non-exclusive royalty-
free license to use that arises by operation of law in the sale of a product. 
						

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Ta b l e o f C o n t e n t s
Chapter 1 MODEL OVERVIEW
1.0 CM140/CM340 Models ........................................................................................ 1-1
2.0 CM160/CM360 Models ........................................................................................ 1-1
Chapter 2 THEORY OF OPERATION
1.0 Introduction .......................................................................................................... 2-1
2.0 Controlhead Model for CM140 and CM340 ......................................................... 2-1
2.1 Power Supplies............................................................................................... 2-1
2.2 Power On / Off ................................................................................................ 2-1
2.3 Microprocessor Circuit .................................................................................... 2-1
2.4 SBEP Serial Interface ..................................................................................... 2-1
2.5 Keypad Keys .................................................................................................. 2-1
2.6 Status LED and Back Light Circuit.................................................................. 2-3
2.7 Microphone Connector Signals ...................................................................... 2-3
2.8 Speaker .......................................................................................................... 2-4
2.9 Electrostatic Transient Protection ................................................................... 2-4
3.0 Controlhead Model for CM160 andCM360 .......................................................... 2-4
3.1 Power Supplies............................................................................................... 2-4
3.2 Power On / Off ................................................................................................ 2-4
3.3 Microprocessor Circuit .................................................................................... 2-5
3.4 SBEP Serial Interface ..................................................................................... 2-5
3.5 Keypad Keys .................................................................................................. 2-6
3.6 Status LED and Back Light Circuit.................................................................. 2-6
3.7 Liquid Crystal Display (LCD) .......................................................................... 2-6
3.8 Microphone Connector Signals ...................................................................... 2-6
3.9 Speaker .......................................................................................................... 2-7
3.10 Electrostatic Transient Protection ................................................................... 2-8
Chapter 3 TROUBLESHOOTING CHARTS
1.0 Troubleshooting Chart for Controlhead CM140/340  ........................................... 3-1
1.1 On/Off ............................................................................................................ 3-1
1.2 Microprocessor .............................................................................................. 3-2
2.0 Troubleshooting Chart for Controlhead CM160/360 ............................................ 3-3
2.1 On/Off ............................................................................................................ 3-3
2.2 Microprocessor .............................................................................................. 3-4
2.3 Display ........................................................................................................... 3-5
2.4 Backlight ........................................................................................................ 3-6 
						

							iv
Chapter 4 CONTROLHEAD PCB/SCHEMATICS/PARTS LISTS
1.0 Allocation of Schematics and Circuit Boards ....................................................... 4-1
2.0 Controlhead CM140/340 - PCB 8488998U01 Schematics .................................. 4-3
2.1 Controlhead PCB 8488998U01 - Parts List.................................................... 4-5
3.0 Controlhead CM160/360 - PCB 8489714U01 Schematics  ................................. 4-6
3.1 Controlhead PCB 8489714U01 - Parts List  ................................................... 4-8 
						

							Chapter 1
OVERVIEW
1.0 CM140/CM340Models
The Controlhead contains the internal speaker, the on/off/volume knob, the microphone connector, 
several buttons to operate the radio, three indicator Light Emitting Diodes (LED) to inform the user 
about the radio status, and a single character 7-segment display for numeric information e.g. 
channel number.
2.0 CM160/CM360Models
The Controlhead contains the internal speaker, the on/off/volume knob, the microphone connector, 
several buttons to operate the radio, three indicator Light Emitting Diodes (LED) to inform the user 
about the radio status, and an 8 character Liquid Crystal Display (LCD) for alpha - numerical 
information e.g. channel number or call address name.  
						

							1-2OVERVIEW 
						

							Chapter 2
THEORY OF OPERATION
1.0 Introduction
This Chapter provides a detailed theory of operation for the Controlhead circuits. For details of the 
trouble shooting refer to the related chapter in this section.
2.0 Controlhead Model for CM140 and CM340
The controlhead contains the internal speaker, the on/off/volume knob, the microphone connector, 
several buttons to operate the radio and three indicator Light Emitting Diodes (LED) to inform the 
user about the radio status and a 7-segment display for numeric information. 
2.1 Power Supplies
The power supply to the control head is taken from the host radio’s 9.3V via connector J803-9, The 
9.3V is used for the LEDs and back light, the 5V is used for the LCD driver and level shifter. The 
stabilized 3V is used for the other parts.
2.2 SPI Interface
The host radio (master) communicates with the control head through its SPI bus. Three lines are 
connected to the shift register (U801):SPI clock (J803-17), SPI MOSI (J803-16) and shift register 
chip select (J803-15).
Shift
RegisterBCD To
7-segment
Mux.
Control
Keypads
DTMF
ResistorsPTT
circuit
2pinspeaker
connector
7-segment
display9.3V
Keypad
Backlight
9.3V Row/ColumnControl line
Boot_res / SCI
DTMF
Row/Column
Boot_res (DTMF-
Column)/ SCI
(DTMF-Row)
Shift
RegisterBCD To
7-segment
Mux.
Control
Keypads
DTMF
ResistorsPTT
circuit
2pinspeaker
connector
7-segment
display9.3V
Keypad
Backlight
9.3V Row/ColumnControl line
Boot_res / SCI
DTMF
Row/Column
Boot_res (DTMF-
Column)/ SCI
(DTMF-Row) 
						

							2-2THEORY OF OPERATION
When the host radio needs to send date to the shift register, the radio asserts the shift register chip 
select and the data is loaded to the shift register. For example, the host radio sends data to change 
display channel or change LED status.
2.3 Keypad Keys
The control head keypad is a four-key design. All keys are configured as two analog lines read by 
µP. The voltage on the analog lines varies between 0V and 3.3 V depending on which key is 
pressed. If no key is pressed, the voltage at both lines is 3.3V. The key configuration can be thought 
of as a matrix where the two lines represent one row and one column. Each line is connected to a 
resistive divider powered by 3.3V. If a button is pressed, it will connect one specific resistor of each 
divider line to ground level and thereby reduce the voltages on the analog lines. The voltages of the 
lines are A/D converted inside the µP (ports PE 6 - 7) and specify the pressed button. To determine 
which key is pressed, the voltage of both lines must be considered.
The same analog lines also support a keypad microphone. A microphone key press is processed in 
the same manner like a control head key press.
2.4 Status LED’s and Back Light Circuit
All indicator LEDs (red, yellow, and green) are driven by current sources. To change the LED status 
the host radio sends a data message to the control head shift register via the SPI bus. The control 
head shift register determines the LED status from the received data and switches the LEDs on or 
off via Q5-Q7.
The back light for the keypad is always on. The back light current for the keypad is drawn from the 
9.3 V source and controlled by two current sources. The LED current is determined by the resistor 
at the emitter of the respective current source transistor.
2.5 Microphone Connector Signals
The MIC_PTT line (J802-3) is grounded when the PTT button on the microphone is pressed. When 
released, this line is pulled to 9.3V by R805. Two transistor stages (Q802, Q801 and associated 
parts) are used to level shift between 9.3V and 3.3V required for the uP while keeping the same 
sense (active low for PTT pressed).
Two of the mic socket lines (J802-2,7) have dual functions depending on the type of microphone or 
SCI lead connected. An electronic switch (U803) is used to switch these two lines between mic 
keypad operation or SCI operation. The switch (mux) is controlled by the uP through J803-20 with 
level shifting (and inversion) provided by transistor Q812. When MUX_CTRL (J803-20) is low the 
electronic switch is in the mic keypad mode. The mic socket (J802) pin 2 is connected to the keypad 
row line that goes to J803-13 and pin 7 is connected to the keypad column line that goes to J803-12. 
When MUX_CTRL (J803-20) is high the electronic switch is in the SCI mode. The mic socket (J802 
pin 2) is connected to the SCI line that goes to J803-4 and pin 7 is connected to the BOOT_RES line 
that goes to J803-11.
The HOOK line (J802-6) is used to inform the uP which type of microphone or SCI lead is connected 
to the microphone socket. The voltage of the HOOK line is monitored by the uP (port PE0, 
MIC_SENSE) through a resistor divider on the main board. When the HOOK line is grounded (on 
hook condition) or floating (2.8V nominal), the uP sets the mux (U803) for keypad operation to allow 
the use of microphones with a keypad. When the HOOK line is connected to 9.3V, the uP sets the 
mux for SCI operation. This mode is also used to select low cost mic operation where the gain of the 
microphone path is increased (on the main board) to compensate for not having a pre-amp in the low 
cost mic. 
						

							Controlhead Model for CM140 and CM3402-3
If the BOOT_RES (J802-7) line is connected to >5V (e.g. 9.3V) at turn-on, the uP will start in boot 
mode instead of normal operation. This mode is used to programme new firmware into the FLASH 
memory (U404 mainboard). 
2.6 Speaker
The controlhead contains a speaker for the receiver audio. The receiver audio signal from the 
differential audio output of the audio amplifier located on the radio’s controller is fed via connector 
J803-1, 2 to the speaker connector P801 pin 1 and pin 2. The speaker is connected to the speaker 
connector P801. The controlhead speaker can be disconnected if an external speaker, connected on 
the accessory connector, is used.
2.7 Electrostatic Transient Protection
Electrostatic transient protection is provided for the sensitive components in the controlhead by 
diodes VR801, VR802, VR803 and VR804. The diodes limit any transient voltages to tolerable 
levels. The associated capacitors provide Radio Frequency Interference (RFI) protection. 
						

							2-4THEORY OF OPERATION
3.0 Controlhead Model for CM160 and CM360
The controlhead contains the internal speaker, the on/off/volume knob, the microphone connector, 
several buttons to operate the radio, three indicator Light Emitting Diodes (LED) to inform the user 
about the radio status, and an 8 character Liquid Crystal Display (LCD) for alpha - numerical 
information e.g. channel number or call address name. 
3.1 Power Supplies
The power supply to the control head is taken from the host radio’s 9.3V via connector J103-9, The 
9.3V is used for the LEDs and back light, the 5V is used for the LCD driver (U3) and level shifter 
(U4). The stabilized 3V is used for the other parts.
3.2 SPI Interface
The host radio (master) communicates with the control head through its SPI bus. Three lines are 
connected to the shift register (U8):SPI clock (J103-17), SPI MOSI (J103-16), shift register chip 
select (J103-15) and LCD driver chip select (J103-18).
When the host radio needs to send date to the shift register, the radio asserts the shift register chip 
select and the data is loaded to the shift register. For example, the host radio sends data to change 
display channel or change LED status.
8pinJACK
connector 9.3V
LCD
Shift
RegisterBacklight
Control
Mux.
Control
Keypads
Keypad
ResistorsPTT
circuit
2-pin speaker
connector
9.3V
LED
Indicators
Row/ColumnControl line
Boot_Res / SCI
DTMF
Row/Column
Boot_Res (DTMF-
Column)/ SCI
(DTMF-Row)
Level
ShifterLCD
DriverLED
Backlight
8pinJACK
connector 9.3V
LCD
Shift
RegisterBacklight
Control
Mux.
Control
Keypads
Keypad
ResistorsPTT
circuit
2-pin speaker
connector
9.3V
LED
Indicators
Row/ColumnControl line
Boot_Res / SCI
DTMF
Row/Column
Boot_Res (DTMF-
Column)/ SCI
(DTMF-Row)
Level
ShifterLCD
DriverLED
Backlight