red LED will remain dimly lit through resistor R066. When an IR command has been successfully received,
then the LED will flash briefly, to inform the user that the button on the handset was pressed correctly.
2
IC Connections
Pin 49 is the I2C bus data input/output for transferring data between I2C devices that are always powered
up. This line is connected to the EEPROM (I005) and the shift register (I004). This line is constantly active
when the TV is powered up and normally changes state between HIGH and LOW.
Pin 48 is the I2C bus clock output for clocking the data to I2C devices that are always powered up. This line
oscillates at a frequency around 30KHz
Pin 52 is the I2C bus data input/output for transferring data between all other I2C devices. This line is
constantly active when the TV is powered up and normally changes state between HIGH and LOW. The
circuit around Q002 performs conversion between the 3V3 levels of the micro and the 5V levels of the
external circuits.
Pin 51 is the I2C bus clock output for clocking the data to all other I2C peripherals/devices. This line
oscillates at a frequency around 30KHz. The circuit around Q005 performs conversion between the 3V3
levels of the micro and the 5V levels of the external circuits.
AVLink/diagnostic Connections
Pin 8 is the Avlink/diagnostics transmit line from the microcontroller to the avlink interface. It is connected to
the base of Q004, used to drive the AVLink line low when transmitting.
Pin 22 is the Avlink/diagnostics receive line from the avlink interface. Diode D001 converts the +5V avlink
levels to the 3.3-volt supply of the micro.
DTT RS232 Connections
Pin 47 is the RS232 transmit line from the microcontroller to the DTT module. It is connected to pin 3 of
connector P005 for the DTT module.
Pin 28 is the RS232 receive line from the DTT module to the microcontroller. It is connected to pin 4 of
connector P005 for the DTT module.
DTT Reset Output Connection
Pin 31 is connected to pin 1 of the DTT connector (P005) and switches low to reset the DTT module.
Shutdown Connection
Pin 1 is used to switch off the deflection stage and mute the amplifiers when a power failure occurs. This
line is normally LOW but switches HIGH when power fails. This causes a voltage to be applied to the EHT
feedback input (pin 50) of I501, simulating an over voltage condition and causing I501 to begin the standby
procedure.
RGB Connections
Pin 41 is the OSD/Teletext RGB blanking signal necessary for allowing insertion of the OSD/Teletext onto
the picture. When this output is high, then the RGB signal will be superimposed onto the current picture.
Pin 40 is the OSD blue signal necessary for displaying BLUE colours for the OSD and Teletext.
Pin 39 is the OSD green signal necessary for displaying GREEN colours for the OSD and Teletext.
Pin 38 is the OSD red signal necessary for displaying RED colours for the OSD and Teletext.
CVBS Connections
Pin 12 is the Composite Video signal input for Teletext, VPS and WSS slicing. It is normally AC coupled
and internally clamped to ensure reliable operation. VPS (video programming system) is necessary when
auto-sorting programmes in Germany/Austria/Switzerland. WSS (wide-screen signalling) is used to indicate
the aspect ratio of the incoming signal. The TV can then use this information to display the picture in the
correct format. |
ACEC
