Controller I/O Pin Configuration And Function; Tuning; Automatic Format Switching And Wss - Daewoo CP-885 Service Manual

Service manual WP 895/895F, CP885/885F

5-4-3 - 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 analogue-to-digital converter.
- Controller I/O pin configuration and function table
name
pin
1 Power
2 AGC
5 Mod SW
6 SECAM L'
7 AFC
8 IR
9 SC1 SW
10 SC2 SW
61 Mute
62 LED
63 KB
64 OCP
To reduce power consumption in stand by mode all ports not used are configured in high impedance mode.

5-4-4 Tuning

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.

5-4-5 Automatic Format switching and WSS

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
configuration
Stand by
Push Pull Low
High impedance
High impedance
High impedance
High impedance
High impedance
High impedance
High impedance
Push Pull
Open Drain
High impedance
High impedance
TV ON
Push Pull High
High impedance
Push Pull
Push Pull
High impedance
High impedance
High impedance
High impedance
Push Pull
Open Drain
High impedance
High impedance
- 50 -
description
Switch OFF / ON SMPS
Tuner AGC level input –
For factory use only
High = Negative
modulation, Low = Positive
modulation (L/L').
Low = L, High =L'
ADC input
Interrupt input
SCART 1 slow switching –
ADC input
SCART 2 slow switching –
ADC input
High = Mute active
Keyboard input – ADC
input
Over Current Protection –
Switch the set to Std by if < 2.