Graphic Orders
SL2F_HD
MOTOROLA
MC68322 USER’S MANUAL
13-55
SL2F_HD
Halftone/Destination Scanline Transfer to Frame
The SL2F_HD graphic order causes the MC68322 to render a scanline table image to a
frame and apply a halftone bitmap in the process. The destination and halftone pixels are
combined as specified by the Boolean code last set by the SET_BOOL_HD graphic order.
The destination frame warp is taken from the graphic order’s frame width (FW) parameter.
The SET_HTBMAP graphic order must previously define the halftone bitmap dimensions.
Halftone tiled patterns are typically anchored to the page. The rendering of a scanline table
may need to take on the halftone pattern starting at various points in the halftone bitmap,
depending on where it is positioned on the page. The halftone parameters HXR, HYR, and
HA define the precise halftone pixel that corresponds to the initial destination address given
in the graphic order. Remember that the initial destination address is not where the first pixel
is drawn—it is the point to which the first bit string specifier’s displacement is added.
HXR specifies the number of pixels remaining to the right edge of the bitmap and HYR
defines the number of scanlines remaining to the bottom edge. HXR and HYR must be in
the following ranges: 1
≤ HXR ≤ HW and 1 ≤ HYR ≤ HH, where HW and HH are the width
and height of the halftone bitmap, respectively. For example, if the starting pixel in the
halftone bitmap is determined to be at the upper left, HXR must be set to HW, and HYR to
HH.
HTTA and SLTA point to the most-significant byte of the first specifier in their respective
tables, and DA, HXR, HYR, and HA refer to the pixel to which the displacement of the first
bit string specifier is added (not necessarily the first bit of the first run). Since both the
scanline table and companion halftone table’s specifiers must be placed at word
boundaries, HTTA and SLTA must be word-aligned.
Related Graphic Orders
SET_BOOL_HD
SET_HTBMAP
PARAMETERS
SIZE
DESCRIPTION
0x15
0x00
DA
FW
HXR
HYR
HA
HTTA
SLTA
Byte
Long Word
Word
Long Word
28 of 32 bits
SL2F_HD Opcode.
Reserved.
Destination physical bit address.
Frame width in bits.
Halftone X remainder.
Halftone Y remainder.
Halftone physical address of the starting pixel.
Companion halftone table physical byte address, word aligned.
Scanline table physical byte address, word aligned.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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