
Philips Semiconductors
PNX15xx Series
Volume 1 of 1
Chapter 11: QVCP
PNX15XX_SER_3
Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Product data sheet
Rev. 3 — 17 March 2006
11-15
2.4.7
PLAN (Semi Planar DMA) Unit
This pool element contains one DMA channel which can be independently assigned
to any layer. By default, this DMA channels is assigned to the rst layer. The DMA
channel is meant for fetching UV data in parallel to the fetching of Y-data by the DMA
unit that is already present inside each layer.
2.5 Screen Timing Generator
The Screen Timing Generator (STG) creates the required synchronization signals for
the monitor or other display devices. The screen timing generator usually operates as
the timing master in the system. However, it is also possible to synchronize the
operation of the screen timing generator to external events i.e., a vertical
synchronization signal. The screen timing generator also denes the active display
region. The coordinate system for the STG is (x, y), with (0, 0) referring to the top left
of the screen. The coordinate (Horizontal Total, Vertical Total) denes the bottom right
of the screen. Horizontal and vertical blanking intervals, synchronization signals, and
the visible display are within these boundaries.
Some of the control parameters that need to be set for the screen timing are:
HTOTAL = Total no. of pixels per line minus one
VTOTAL = Total no. of lines per eld minus one
HSYNCS/E = Start/End pixel position of horizontal sync (Hsync)
VSYNCS/E = Start/End line position of vertical sync (Vsync)
HBLNKS/E = Start/End pixel position of horizontal blanking interval
VBLNKS/E = Start/End line position of vertical blanking interval
The following rules apply to the register settings specifying the screen timing using
the above control parameters:
total number of pixel per line: HTOTAL + 1
total number of lines per eld: VTOTAL + 1
0,1 < HBLNKS <=HTOTAL
0,1 < HSYNCS <= HTOTAL
0 < VBLNKS <= VTOTAL
0 < VSYNCS <= VTOTAL
Hsync - must be asserted or negated for at least one clock
Vsync - must be asserted or negated for at least one scanline
Hblank - must be asserted or negated for at least two clocks
Vblank - must be asserted or negated for at least two scanlines