GM5060 Datasheet, PDF (56/85 Pages) List of Unclassifed Manufacturers – GRAPHICS PROCESSING IC PROVIDING HIGH QUALITY IMAGES FOR LCD MONITORS

Genesis Microchip
gm5060 / gm5060-H Data Sheet
4.13.2.1. Display Free-Run Mode
Free-run mode is used when there is no valid input timing (i.e. to display OSD messages or a
splash screen). In free-run mode, the display timing is determined only by the values
programmed into the display window and timing registers. The DDDS is programmed for open-
loop operation and no synchronization is attempted.
4.13.2.2. Frame Sync Mode
Display synchronization is normally done using frame sync mode. In this mode, a ‘lock event’
(defined in the input timing) determines the frame boundaries in the display timing (display lock
load).
Input Lock Event and Display Lock Load
The programmable input Lock Event and display Lock Load parameters represent the mechanism
for frame synchronization. The Lock Event represents a chosen pixel location within the input
field or frame. When the Lock Event location is reached, the gm5060 Display Timing Generator
is reloaded with the Lock Load values. Hence, the display timing is “corrected” or “aligned” to
the proper location. This process automatically synchronizes the output to the input, and when
properly programmed, prevents gm5060 internal buffer overflow / underflow when no frame
buffer is present. The following diagram shows the process when the display frame rate is locked
to 1x the input frame rate.
Input Data
VS
LOCK EVENT >
Zoomed Display Data
Output is
VS
re-synchonized
to the input
VS
LOCK EVENT >
Output is
VS
re-synchonized
to the input
February 2002
48
C5060-DAT-01G