Service manual
- Controller I/O pin configuration and function
There exist different kinds of ports. The universal ports serve as digital I/O and have additional special input and output functions. A subset of the universal ports serves as input for the
- Controller I/O pin configuration and function table
pin | name | configuration | description | ||
Stand by | TV ON | ||||
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1 | Power | Push Pull Low | Push Pull High | Switch OFF / ON SMPS | |
2 | AGC | High impedance | High impedance | Tuner AGC level input – | |
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| For factory use only | |
5 | Mod SW | High impedance | Push Pull | High = Negative | |
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| modulation, Low = Positive | |
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| modulation (L/L’). | |
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6 | SECAM L’ | High impedance | Push Pull | Low = L, High =L’ | |
7 | AFC | High impedance | High impedance | ADC input | |
8 | IR | High impedance | High impedance | Interrupt input | |
9 | SC1 SW | High impedance | High impedance | SCART 1 slow switching – | |
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| ADC input | |
10 | SC2 SW | High impedance | High impedance | SCART 2 slow switching – | |
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| ADC input | |
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61 | Mute | Push Pull | Push Pull | High = Mute active | |
62 | LED | Open Drain | Open Drain |
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63 | KB | High impedance | High impedance | Keyboard input – ADC | |
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| input | |
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64 | OCP | High impedance | High impedance | Over Current Protection – | |
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| Switch the set to Std by if < 2. | |
To reduce power consumption in stand by mode all ports not used are configured in high impedance mode.
The AFC information is supplied by the demodulator IC, and becomes available on VCT pin 7 for controlling software. The controlling software uses this information for tuner frequency tracking ( automatic following ). The AFC window is typically between 50 KHz and 100 KHz.
The minimum frequency step of the tuner is 50 Khz.
This AFC function is disabled when a program is tuned using the direct frequency entry or after fine tuning adjustment. Therefore it is recommended to tune channel with the TV search function ( manual or ATSS ) or using the direct channel entry to enable the Automatic Frequency Control.
When AUTO mode is selected by the user, the television will automatically select a mode for the user. The format information is supplied by SCART pin 8 level when in AV mode or by WSS data. The signal contains codes as defined in the WSS European Telecommunication Standard, ETS 300 294. Briefly, the signal is received at the beginning of line