Graphic Orders
SL2BB_HD
MOTOROLA
MC68322 USER’S MANUAL
13-51
SL2BB_HD
Halftone/Destination Scanline Transfer to Banded Bitmap
Note: * Denotes A Parameter That The MC68322 Updates When The Frame Crosses A Band Boundary.
The SL2BB_HD graphic order causes the MC68322 to render a scanline table image to a
banded bitmap 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 SET_BBMAP graphic order must previously define the destination
banded bitmap parameters and the SET_HTBMAP graphic order must do the same for 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—when the B2T flag is clear, it is the point to which the first bit string specifier’s
displacement is added and when the B2T flag is set, the point immediately to the right of the
last bit string specifier’s run.
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 (or top edge, when the B2T
flag is set). 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, when the B2T flag is clear, 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; if instead a 180
° page is
being rendered and the B2T flag is set, HXR must still be set to HW, but HYR must be set
to one.
PARAMETERS
SIZE
DESCRIPTION
0x35
BAND*
DA*
HXR*
HYR*
HA*
HTTA*
SLTA*
Byte
Long Word
Word
Long Word
28 of 32 bits
SL2BB_HD Opcode.
Band number when graphic order is executed.
Destination logical bit address.
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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