ST92196A STMicroelectronics, ST92196A Datasheet - Page 151

• 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

OSD CONTROLLER (Cont’d)
The real time control provides:
– A continuous search of matching values be-
– A display interrupt generation when the match
– In “full OSD mode”, if the TE bit in the OSDER
8.5.8.9
Continuous Mode:
– When the line match condition is detected, an in-
Let us then assume the TE bit in the OSDER reg-
ister is set. When the interrupt is executed:
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- ON SCREEN DISPLAY CONTROLLER (OSD)
tween Scan line and Event Line (this condition
being evaluated at each TV line start).
condition is detected.
register is set, the switch from one row buffer to
the second row buffer when the match occurs. If
the TE bit in the OSDER register is reset, when a
matching condition occurs, the previous row buff-
er will be kept.
terrupt is sent to the CPU.
Handling
the
Row
Buffers
in
– The Event Line value must be programmed to
– The next Row Buffer content must be filled up by
Let us then assume the TE bit in the OSDER reg-
ister is reset. When the interrupt is fetched:
– The Event Line value must be programmed to
– The Next Row Buffer content might be filled up
– The content of the current Row Buffer is NOT
Note: In case the TE bit in the OSDER register is
kept reset, there is no need to manage the second
row buffer as it will never be used.
the next desired value.
the data of the next row to display. The next row
buffer is easily identified using the BUFL bit in the
OSDFBR register.
the next desired value.
by the data of the next row to display, if desired.
displayed but simply ignored as it should have al-
ready been displayed in a previous cycle.