Tait TM8235, Service Manual

Page: 93 / 578

TM8100/TM8200 Service Manual Circuit Descriptions 93
© Tait Electronics Limited June 2006
Figure 3.14 Block diagram of the control-head board with graphical display
On/Off
Keypad
Volume
Potentio-
meter
LCD
LCD Loom LCD
Connector
Function
Key and
Status LEDs
Keypad
Backlighting
LEDs
Main
Keypad
LED
Lenses
On/Off Key
Function/
Scroll/
Selection
Keys
Contact made
when key
pressed
Light Pipes
Control-
Head
Options
Connector
Microphone
Connector
+13.8 V
MIC RXD
MIC TXD
MIC GPIO1
MIC PTT
MIC RX AUD
MIC AUD IN
Protection
Circuitry
+3V3 +13V8
COL
ROW
BRIGHT
BRIGHT
HEATER
BACKLIGHT
+3V3
Analog/
Digital
Converter
Speaker
Connector
ASYNC UART
JTAG
+3V3
Soldering
Pads
AGND
DGND
Concealed
Microphone
Speaker
MIC–
MIC+
AGND
Power
Supply
+3V3 +1V5
+1V5
+3V3
+13V8
CH RXD
CH TXD
CH GPIO1
CH PTT
CH ON OFF
+13V8
SPK+
SPK– SPK–
SPK+
Speaker Leads
Microphone
Leads
DGND
AGND
CH SPI DO
+3V3 SENSE
+13V8
CH ON OFF
VOL WIP DC
RESET
AGND
AGND
Power
Switches
TEMP SENSOR
CH RX AUD
CH MIC AUD
Boot
Flash
BIRDIE
FPGA CLOCK
System
Clock
SRAM
CONTROL
ADDRESS
DA
TA
Flash
Memory
Control-
Head
Connector
Control-Head Board
DEBUG
FPGA JTAG Signals:
FPGA JTAG TCK
FPGA JTAG TMS
FPGA JTAG TDO
JTAG FPGA TDI
RESET
CONTROL
DISPLAY CONTROL
Constant-
Current
Drivers
WATCHDOG TRIGGER
POWER ON/OFF SENSE
BRIGHT
BRIGHT
ENABLE
HEATER
BACKLIGHT
Contact made
when key
pressed
Signal Types:
analog
clock
digital
asynchronous
serial data
synchronous
serial data
FPGA
Microphone
Pre-amplifier
and Audio
Switching