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TVP5150AM1 design questions

Martin Stankus
Prodigy 50 points
Other Parts Discussed in Thread: TVP5150AM1

Hello,

I'd like to ask some questions regarding TVP5150AM1 in BT.656 mode.

1.) What is the resolution of NTSC signal with standard (v04.8C.AA) and square pixel (v04.A1.02) firmwares? Resolution with standard firmware will be something like 720x480. Vertical resolution is according to my measurements not 480, but something slightly different... 483? 486? Its rather hard to check with ordinary scope.

2.) Can you explain following flags in SR1 and SR2 registers? Description in datasheet is way too brief.

Status register #1, bit 6: Line-alternating status

Status register #2, bit 6: Weak signal detection

Status register #2, bit 5: PAL switch polarity

Thank you.

Best regards,

Martin Stankus

  • 0
    TI__Mastermind 43875 points

    Martin,

    Sorry for the delay in responding.

    If you check section 3.11 of the latest datasheet you can find the active horizontal pixel counts for non-square pixel modes, which are 720.

    Square pixel modes should be 768 pixels wide.

    Vertically NTSC is 480 lines per frame, or 240 lines per field. PAL should be 576 per frame, or 288 per field.

    You can also look at the AVID start/stop registers to determine how many pixels and lines will be sent (subtract stop from start). See section 3.13 in the datasheet. Note for embedded sync the output conforms to ITU656.

    Line alternating status is a useless register and returns the stats of the color carrier line phase. PAL switch polarity is also a useless register.

    Weak signal indicates that the source signal is weak and noisy hence verious internal registers and algorithms have been switched to modes best suited to allow locking to weak signals.

    BR,

    Steve