Service manual

CP-850FX Service Manual
Europe R&D
55
 Attenuation Measurement and Compensation
 Group Delay Measurement and Compensation
 Exact Decoding of Echo Disturbed Signals
5.5.3 PORTS
 One 8-bit I/O-port with open drain output and optional I 2 C Bus emulation support (Port 0)
 Two 8-bit multifunction I/O-ports (Port 1, Port 3)
 One 4-bit port working as digital or analogue inputs for the ADC (Port 2)
 One 2-bit I/O-port with secondary functions (P4.2, 4.3, 4.7)
5.5.4 μ-CONTROLLER I/O PIN CONFIGURATION AND FUNCTION TABLE
CONFIGURATION
PIN NAME
STAND BY TV ON
DESCRIPTION
3
S/SW2 Open Drain Open Drain
4
S/SW2 Open Drain Open Drain
5
OCP Open Drain Open Drain Over Current Protection
8
RESET out Low Open Drain Reset video IC’s
15
S/SW1 High impedance High impedance ADC input
16
AGC in High impedance High impedance AGC input – ADC input
17
KEY High impedance High impedance Keyboard input – ADC input
18
AFT High impedance High impedance AFT input– ADC input
21
Mod SW High impedance Push Pull
High = Negative modulation, Low =
Positive modulation (L/L’).
22
SECAM L’ High impedance Push Pull Low = L, High =L’
23
IR High impedance High impedance Infrared Interrupt input
24
SOUND INT Input input
Sound interrupt input – edge
triggered
47
Sound Mute Push Pull - Low Push Pull - High Low=Mute
48
AGC out -- PWM out Control tuner AGC (TOP)
50
Relay Push Pull - Low Push Pull - High
51
LED Push Pull Push Pull
Low : LED Red
High : LED Green
52
Power Push Pull - Low Push Pull - High
SMPS operation mode
High=ON, Low=ST-BY
5.5.5 TUNING
The AFC information is supplied by the demodulator IC, and becomes available on SDA55xx pin
15 for controlling software. The controlling software uses this information for tuner frequency
tracking ( automatic following ). The AFC windows 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.
#4 #3 Source
L L Tuner
L H AV2-16/9
H L AV2-4/3
H H AV2-4/3
Downloaded From TV-Manual.com Manuals