ST92196A STMicroelectronics, ST92196A Datasheet - Page 137

• 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)
8.5.7 Programming the Mouse Pointer
The Mouse Pointer is programmed using two con-
trol bits stored in registers, and three 16-bit words
located in OSDRAM
The mouse pointer can be defined as any of the
ROM Font characters. The 18x26 matrix is used to
represent it.
Mouse Pointer Attributes
The three 16-bit word attributes are located in OS-
DRAM:
– Mouse Coding Data
– Mouse Pointer Vertical Position
– Mouse Pointer Horizontal Position
Mouse pointer interrupt control
The Mouse Pointer has a dedicated interrupt
source which uses the same interrupt line as the
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- ON SCREEN DISPLAY CONTROLLER (OSD)
(Figure
59).
OSD. Both interrupts (Mouse Pointer and OSD)
are simply ORed at hardware level and forwarded
to the CPU.
The Mouse pointer interrupt is generated as soon
as the Mouse matrix processing is completed.
The Mouse Pointer interrupt generation is auto-
matically enabled as soon as the Mouse Pointer is
activated.
To help identify the actual interrupt source, a flag
(MOIT) is associated with the Mouse Pointer inter-
rupt: this flag is activated when the mouse inter-
rupt is generated and must be cleared by software.
This bit is not the image of the interrupt transient
condition but it keeps trace of the interrupt event
until the software erases it. This bit must be reset
by writing to the Enable register. The Mouse Point-
er interrupt is generated regardless of this flag val-
ue.