GS4911B_09 Datasheet, PDF (44/119 Pages) Gennum Corporation – HD/SD/Graphics Clock and Timing Generator with GENLOCK

PCLK
LUMA DATA OUT
CHROMA DATA OUT
H
V
F
3FF
000
3FF
000
H Signal Timing
Typical H Timing
Alternative H Timing
000
XYZ (eav)
3FF
000
XYZ (eav)
3FF
H:V:F TIMING - HD 20-BIT OUTPUT MODE
000
000
Figure 3-4: Example H Blanking, V Blanking, and F Digital Input Timing from
an SDI Deserializer
Timing for Graphics Formats
The GS4911B/GS4910B is pre-programmed to recognize the timing for 16 different
graphics formats presented to the input reference pins. These graphic formats are
described in Section 1.4 on page 20.
The supported graphics standards are all progressive, and do not use the FSYNC signal.
Therefore, FSYNC should be held LOW by the application layer. The VESA formats
supported have a 0.5% frequency tolerance.
VSYNC transitions are typically co-timed with the leading edge of HSYNC. The duration
and polarity of these signals for each format is listed in Table 1-2.
NOTE: The user must ensure that the input HSYNC polarity for VID_STD [5:0] = 47 and
49 – 54 be active LOW.
3.4.2 10FID
The 10FID input is a reset pin, which can be used to reset the divider for the 10FID output
signal. In the GS4911B, the 10FID input pin will also reset the divider for the AFS output
signal. This default setting may be modified using the Audio_Control register of the host
interface (see Section 3.12.3 on page 79).
The GS4911B will reset the phase of the audio clocks to the leading edge of the H Sync
output on line 1 of every output frame in which the 10FID input is HIGH. This enables
the user to reset the phase of the dividers when generating custom signals via the host
interface (see Section 3.7.2.1 on page 65).
If the input reference format does not include a 10 Field ID signal, the external 10FID
input pin should be held LOW.
The timing of the 10FID input signal is shown in Figure 3-5.
000
000
XYZ (sav)
XYZ (sav)
GS4911B/GS4910B HD/SD/Graphics Clock and Timing
Generator with GENLOCK
Data Sheet
36655 - 5
June 2009
44 of 119