ST92196A STMicroelectronics, ST92196A Datasheet - Page 122

• Manufacturer Part Number: ST92196A
• Description: 8/16-bit Mcu For Tv Applications With Up To 96k Rom, On-screen-display And 1 Or 2 Data Slicers
• Manufacturer: STMicroelectronics

8.5.3.12 Mouse Pointer
The Mouse Pointer icon is built as an 18x26 dot
matrix; it is fully user definable, selected from any
of the OSD characters in Font ROM memory (ex-
cept 00h). This allows a multiple mouse configura-
tion.
The Mouse Pointer dots are processed like any
9x13 character, i.e. any dot is displayed on both
fields and represents a final 2x2 pixel area on the
screen. The Mouse Pointer represents a 18x26
character displayed in 2Y-2X size.
Only the Mouse Pointer foreground is displayed.
The Mouse Pointer background is transparent.
The Mouse Pointer dot processing includes the
standard foreground pixel processing and also the
rounding and fringe. The algorithms used are the
same as for characters (for more details, refer to
the rounding and fringe section above, assuming a
9x13 character matrix case extended to an 18x26
matrix).
The Mouse Pointer uses one of the foreground
Palette entries to define its pixel color. All features
- ON SCREEN DISPLAY CONTROLLER (OSD)
of the foreground Palette are retained except the
Underline.
The priority of all color layers is from highest-to-
lowest:
Mouse foreground, Mouse fringe, OSD characters
and border.
8.5.4 Horizontal and Vertical Sync
8.5.4.1 Pixel Clock Control
The Pixel clock is issued from a frequency multipli-
er which is locked to the main crystal frequency.
The synthesized frequency is software program-
mable (4-bit value defining the multiplying factor)
which provides flexibility for supporting various ap-
plication conditions, from a basic 4/3 screen for-
mat and a “1H” horizontal sweep to a 16/9 format
with a “2H” sweep, interlaced or progressive scan-
ning. For more information, refer to the Timing and
Clock Controller chapter.
Note: It is recommended to wait for a stable clock
(approx. 35 ms) from the frequency multiplier be-
fore enabling the OSDRAM controller.
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