Table of Contents
Advertisement
The SuperH can access the UGM directly via the Q2
Figure 1-4
Unified System Bus Interface (UGM Directly Accessible by
1 . 3 . 2
Realtime Operation
Use of Double-Buffering Architecture: The use of a double-buffering architecture that
allows switching between the drawing buffer and display buffer in frame or field units, together
with the use of EDO page mode DRAM for the UGM, enables realtime operation by alternating
display processing with high-speed drawing processing.
• Double-buffer control
Kinds of double-buffer control
• Auto display change mode: Mode in which priority is given to display frame
switching. If drawing is in progress when frame switching is to be performed, drawing
is forcibly terminated midway.
• Auto rendering mode: Mode in which display switching is not performed until
drawing ends. If drawing does not end within one frame, drawing is continued without
interruption and frame switching is performed at the frame boundary immediately after
drawing is completed.
• Manual display change mode: Mode in which display frame switching and the
start of drawing are controlled by software. When the display area change bit (DC bit) is
set after drawing is completed, frame switching is performed at the next frame boundary.
Double-buffer switching timing
• Non-interlace mode: Scanning system in which one frame is composed of one field.
Double-buffer switching is performed in units of a frame.
• Interlace sync mode: Scanning system in which one frame is composed of two
fields. Double-buffer switching is performed in units of a frame.
• Interlace sync & video mode: Scanning system in which one frame is composed
of two fields. Double-buffer switching is performed in units of a field.
UGM (Unified Graphics Memory)
Frame buffer 0
Binary work area
SuperH via Q2)
Frame buffer 1
Binary/multi-valued
source
Display list
5
Advertisement
Table of Contents
