SPC8106 S-MOS Systems, SPC8106 Datasheet - Page 157

• Manufacturer Part Number: SPC8106
• Description: LCD/CRT VGA CONTROLLER
• Manufacturer: S-MOS Systems

bits 7-0
bit 3
bit 2
bit 1
bit 0
SPC8106
37 Sprite/HW Cursor Address Low Register RW
Sprite/HW
Cursor Addr
Bit 7
38 Sprite/HW Cursor Function Register RW
n/a
411-1.0
Sprite/HW
Cursor Addr
Bit 6
n/a
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Sprite/HW Cursor Address Bits [7:0]
These are the least significant 8 bits of the address location of the top left hand point of the sprite
or hardware cursor pattern stored in memory. The complete 18 bit memory address for the sprite/
HW cursor is formed as follows:
The row bits represent the current row of the sprite/HW cursor being fetched (0-63). The column
bits represent the upper 3 bits of the horizontal position of the current pixels being fetched from
memory, with each fetch retrieving 16 bits from memory or 8 pixels of the Sprite/HW cursor image.
Vertical Doubling Enable
When this bit is set to 1, the displayed image of the sprite/HW cursor is doubled in the vertical
dimension, providing the sprite/HW cursor function is enabled. When this bit is set to 0, the sprite/
HW cursor is not doubled. If the sprite/HW cursor function is not enabled, then this bit has no
effect. Note that the origin of the sprite/HW cursor is not affected by enabling vertical line doubling.
Horizontal Doubling Enable
When this bit is set to 1, the displayed image of the sprite /HW cursor is doubled in the horizontal
dimension, providing the sprite/HW cursor function is enabled. When this bit is set to 0, the sprite/
HW cursor is not doubled. If the sprite/HW cursor function is not enabled, then this bit has no
effect. Note that the origin of the sprite/HW cursor is not affected by enabling horizontal line dou-
bling.
HW Cursor/Sprite Select
Provided that the sprite/HW cursor function is enabled (Auxiliary Register 05 bit 5 = 1), when this
bit is set to 0, the sprite function is selected, and when this bit is set to 1, the hardware cursor func-
tion is selected. If the sprite/HW cursor function is not enabled, then this bit has no effect.
Sprite Palette Scheme Select
This bit is used to select the palette scheme used for the sprite. The 2 bit sprite pixel color may rep-
resent either 1 of 4 colors, or 1 of 3 colors plus transparency. Provided that the sprite/HW cursor
function is enabled (AUX[05] bit 5 = 1), when this bit is set to 0, the sprite pixel bits select 1 of 4
sprite palette entries as the value of the currently displayed pixel. When this bit is set to 1, the sprite
pixel values 1 to 3 select sprite palette entries 1 to 3 respectively, and sprite pixel value 0 selects
transparency, setting the current pixel to the value of the displayed image behind the sprite pixel.
The sprite palette entries 0-3 are accessed via the internal LUT register address space when
AUX[0B] bit 3 = 1, at LUT index values 0Ch to 0Fh, respectively. See “LCD Gray Scale/Color
Lookup Table Registers” on page 116 for details.
MA[17:9]
MA[8:3]
MA[2:0]
Table 0-57 Sprite/HW Cursor Address Bits
Sprite/HW
Cursor Addr
Bit 5
n/a
Sprite/HW Cursor Address [8:0]
Row [5:0]
Column [2:0]
Sprite/HW
Cursor Addr
Bit 4
n/a
X12-SP-001-07
Sprite/HW
Cursor Addr
Bit 3
Vertical
Doubling
Enable
Horizontal
Doubling
Enable
Sprite/HW
Cursor Addr
Bit 2
Hardware Functional Specification
HW Cursor/
Sprite Select
Sprite/HW
Cursor Addr
Bit 1
Sprite
Palette
Scheme Sel
Sprite/HW
Cursor Addr
Bit 0
SP1-115