MC68HC705T16 MOTOROLA [Motorola, Inc], MC68HC705T16 Datasheet - Page 72

• Manufacturer Part Number: MC68HC705T16
• Description: High-density complementary metal oxide semiconductor (HCMOS) microcontroller unit
• Manufacturer: MOTOROLA [Motorola, Inc]

9
The video mute function, when enabled, blocks off all TV video signals; but OSD signals remain.
This feature can be used when, for example, the selected channel does not have any valid
broadcast signals. Rather than displaying snow flakes on the screen, the OSD mute function can
be activated to cover up the snow flakes and replace them by one of three color selections: black,
green or blue. Video mute can be synchronized with vertical flyback signal so that muting always
occurs on vertical flyback boundary to avoid inconsistent display in the same display field, be it
even or odd. To facilitate this, OSD interrupt activated by the leading edge of vertical flyback is
implemented. Whenever the video mute function is activated, fast blanking signal will be
constantly activated until video mute function is deactivated. As a result, half tone feature is
disabled while video mute is activated.
Ten pins are used for the OSD module; HFLBK, VFLBK, VCO, RP, FBKG, R, G, B, I, and HTONE.
The I and HTONE pins are shared with port PF2 and PF3 respectively. HTONE (half tone) is used
to create transparent background effect on the screen.
OSD registers are divided into four groups; with characters register group defining individual
character features, frame register group defining frame features, row register group defining
individual row features, and finally status register carrying the status of the whole OSD module.
9.2
Frame/Row Features
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MOTOROLA
9-2
PLL-based clock source
Four display row buffers
Programmable R/G/B, I, fast blanking, and half tone output polarity and H/V sync input polarity
Programmable row V and frame H start positions
12x16 or 16x16 character dot matrix selection on per row basis
32 (12x16 dot matrix) or 24 (16x16 dot matrix) symbols per row
8 common color palettes for both symbol color and background color
16 color selections per palette
Frame fade in and fade out feature for smooth display appearance and disappearance
Four row character size selections: 1Hx1V, 2Hx2V, 3Hx3V, and 4Hx4V
Row character black-edge features: bordering or shadowing
Double scan mode support for non-interlaced scan TV system
Half tone capability for creating transparent background effect
Video mute. Three color selections for video mute: black, green, and blue
Features
ON-SCREEN DISPLAY
MC68HC05T16
TPG