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NXP Semiconductors
PNX15xx/952x Series
Volume 1 of 1
Chapter 20: 2D Drawing Engine
PNX15XX_PNX952X_SER_N_4
NXP B.V. 2007. All rights reserved.
Product data sheet
Rev. 4.0 — 03 December 2007
20-626
In the following example, the data stream for a 5*6 font requires 1 DWORD to be sent to
the Engine.
Since font data starts on a byte boundary, a source shift parameter is not required.
The Width eld of the BltSize register determines how many host bits will be
processed before advancing to the next scanline. There are no pad bits between data
bits of adjacent scanlines - the data is highly packed. Excess bits in the very last
DWORD
of host data will be discarded. The Engine will require
(BltSize.Width*BltSize.Height +31)/32
DWORDS
for each glyph drawn. Mono Bitmaps sent to the Engine from Windows are
not necessarily byte aligned on the left or right edges. The starting and ending bits of
each scanline may be in the middle of a byte.
For mono bitmaps, the ve LSBs of the SrcLinear register determine which bit in the
rst DWORD has the rst valid data bit. The BltSize.Width register determines how
many bits will be expanded/drawn for each scanline. The host will send
(BltSize.Width + (SrcLinear&31) + 31)/32
DWORD
s for each scanline. The Engine will discard unused bits in the last DWORD of
each scanline as pad bits. The driver must always send the correct number of
DWORD
s for each scanline in the bitmap.
3.1.3
Mono BLT Register Setup
To deal with both host-to-screen mono bitmap and text data in a general manner, the
Engine uses up to eight parameters as shown in
Table 2.31
0
Data Stream:00110001001001111010000110000110
Rendered Font:
10000
11010
10000
10010
01110
01100
Note the 2 pad bits (25 & 24) in the last byte.
Table 2: Mono Bitmap & Text Data Parameters
Parameter
Description
DstXY or DstLinear
Species the drawing destination on the screen
SrcLinear
The three LSBs specify the leading pad bits in the rst
byte of data on each scanline.
DstStride
Species the number of pixels between scanlines in the
destination
MonoHostFColor
Foreground color
MonoHostBColor
Background color