Specifications

TPF1.3A LA

9. Troubleshooting

3. Function description:

MM tuner is used to receive RF wave and output CVBS and 2nd IF signal. CVBS is to video decoder

(SAA7119) for color process, 2nd IF is to sound decoder (MSP3415) for audio process. The tuner control is via IIC ex.

channel tuning..

Standard TV input (Tuner, S-video, CVBS) is processed by SAA7119, But YPbPr, SDTV and HDTV(480i, 576i,

480p,576p,720p,1080i), is done by scaler MST51502LADC. But the signal is still link to SAA7119 if PIP (video in graph)

function is requested. Then all YPbPr signal processed by SAA7119 could be the PIP video source. (* May use down

sampling in HD0)

MV protect is decoded by scaler.

Video decoder SAA7119, is in charge of color decoding, could support PAL, NTSC and SECAM world wide

system. Compare to SAA7118, SAA7119 improve some picture quality, like V-chip CC I2C read-back, LTI, CTI, skin tone

correction(see task A), also the HD0 is supported.

Sound decoder MSP3415 is responsible to sound decode of tuner 2

IF. It has one 2nd IF, one loudspeaker audio

sources input. Due to the input port limitation, a MUX is added for AV source select( PC audio in is sent to msp3415). If

the post audio amplifier is gain fixed type then the volume adjust will be on MSP3415.

Scaler MST51502L besides scaling function, PIP, 3D de-interlacer, color enhance are major feature.

Even de-interlacer is not so good but for static picture is enough to avoid image sticking.

The scaler structure limitation, the PIP source only from “video port”, 8 bits or 16 bits. The sub window /PIP size can

enlarge to half screen.

MCU, NT68F632AL, is 128K flash ROM inside. Power control, RC5 I/O, and key function all done by here, more detail

function will description in chapter 4.later.

All chip communication is by IIC (SDA/SCL), and ISP is via DDCIIC.

Circuit Description

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