saa6712e NXP Semiconductors, saa6712e Datasheet - Page 48

• Manufacturer Part Number: saa6712e
• Description: Xga Rgb To Tft Graphics Engine
• Manufacturer: NXP Semiconductors

Philips Semiconductors
8.8
8.8.1
If ovl_syncs_active is HIGH, the vertical and horizontal
sync signals for the external OSD controller are generated.
The flag ovl_insert_active switches on the insertion of the
information at the overlay port provided by an external
OSD controller into the data stream at the position defined
by ovl_v_offset, ovl_hs_start, and ovl_hs_latency
(see Fig.13).
1999 Aug 25
handbook, full pagewidth
XGA RGB to TFT graphics engine
Overlay port
O
VERLAY INSERTION
one line Vsync
ovl_v_length
ovl_vs_start
ovl_hs_start
Fig.13 Overlay window positioning.
ovl_hs_latency
OUTPUT FRAME
48
The incoming data from ports ovl0 and ovl1 is replaced by
the defined colour information and treated as a double
pixel, which will be inserted into the data stream if OVACT
is set. The pixel at port 0 is then the left pixel, and the pixel
at port 1 is the right pixel. The sampling of the ports ovl0
and ovl1 is done on the positive edge of OVCLK in the
event that sample_edge is asserted, otherwise on the
falling edge of OVCLK.
ovl_v_offset
OVERLAY
WINDOW
ovl_h_length
MHB258
Preliminary specification
SAA6712E