pnx1500 NXP Semiconductors, pnx1500 Datasheet - Page 625

• Manufacturer Part Number: pnx1500
• Description: Pnx15xx Series Connected Media Processor
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Volume 1 of 1
PNX15XX_SER_3
Product data sheet
3.1.2 Mono Expand
Alpha values in 32-bit pixels are always in the upper byte of the
The Engine needs to deal with two types of monochrome data from the host: fonts
and bitmaps. The primary difference between fonts and bitmaps is how data is
padded to byte boundaries.
First, it is worthwhile to note the bit ordering of monochrome data in a
the left most pixel, bit 24 is the right most pixel. It is (unfortunately) a mish-mash of
data formats since pixels in a byte are big-endian, but bytes are little-endian ordered.
Thus, in a
Fonts can be transferred to the drawing engine in a highly packed format with no pad
data between bits on adjacent scanlines. Pad is added after the last bits in the last
data byte. Since the font data in system memory always begins on a byte boundary,
the host processor can easily arrange to deliver a series of 32-bit aligned
the Engine. This font format has been widely used by Microsoft since Windows 95.
// now update the destination
if (BltCtl.A[3] == 0)
begin
Dst.red = clamp(Src.red + (1 – Src.alpha) * Dst.red) ;
Dst.green = clamp(Src.green + (1 – Src.alpha) * Dst.green) ;
Dst.blue = clamp(Src.blue + (1 – Src.alpha) * Dst.blue) ;
// optionally update the dst alpha
if (BltCtrl.A[2])
Dst.alpha = clamp(Src.alpha + (1 – Src.alpha) * Dst.alpha);
end
else
begin
Dst.red = clamp(Src.red);
Dst.green = clamp(Src.green);
Dst.blue = clamp(Src.blue);
// optionally update the dst alpha
if (BltCtrl.A[2])
Dst.alpha = clamp(Src.alpha)
end
bit7, bit6, bit5,... bit0, bit15, bit4F4... bit8, bit 23... bit16, bit31... bit24
DWORD
, bits are processed in the following order:
Rev. 3 — 17 March 2006
Chapter 20: 2D Drawing Engine
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
PNX15xx Series
DWORD
DWORD
.
DWORD
. Bit 7 is
s to
20-9