CIP 3250A
ADVANCE INFORMATION
the polarity of the Fast Blank signal can be changed via
Table 2–1: Source selection of soft mixer
2
2
I C register <12>MIXAMP. The I C register
<11>FBLOFF influences the phase delay between the
RGB path and the Fast Blank signal (see Fig. 2–4).
<11>
<06>
PASSYUV
Fast Blank
signal
Source
PASSRGB
0
X
0
1
X
RGB
Additionally, a delay of –1 to 2 clocks between the Fast
Blank signal and the RGB-path is programmable via I C
register <16>FBLDEL. By selecting a positive delay,
shadowing of characters can be obtained, if the back-
ground color of the RGB-path is set to black.
2
1
MIX
X
YUV/RGB
YUV
1
X: don’t care
With the built-in linear mixer, the CIP 3250A is able to
support simple AB roll techniques between analog input
(A) and digital YUV input (B):
2.7.2. Fast Blank Monitor
2
VideoOut = A * (1 – FBLMIX/32) + B * FBLMIX/32,
controllable via the Fast Blank signal (FBL):
Bits 0 to 3 of I C register <27> are monitoring the analog
2
FastBlankinput. ReadingI Cregister<27>Fig. 2–5dis-
plays the contents depending on the analog FBL input
signal.
FBLMIX = INT[(FBL – FBLOFF)* MIXAMP/2] + 16,
analog fast
blank input
with FBL of values from 0 to 63. The mixing coefficient
FBLMIX resolves 32 steps within the range from 0 to 32
(dependent on step response chosen via I C register
2
reading I C
register <27>
2
<12>MIXAMP) (see Fig. 2–4).
0
0
0
0
1
1
0
1
1
0
0
1
0
0
1
1
0
0
0
0
<27>FBLSTAT
<27>FBLRISE
<27>FBLFALL
<27>FBLHIGH
2
When the I C register bit <16>FBLCLP is enabled, the
soft mixer operates independently of the analog Fast
Blank input. FBL is clamped to digital 31 (see Fig. 2–4).
Mixing between RGB-path and YUV-path is controllable
Fig. 2–5: Fast Blank Monitor
2
via the I C register <11>FBLOFF.
2.8. FSY Front Sync and AVI Active Video In
FBL (0...63)
– DIGIT 2000 chroma sync detection
– DIGIT 2000 throughput of 72-bit data and clock
– skew data input for DIGIT 2000
FBLMIX
32
1/2
0
1
6
6
0
31
16
– skew data input for DIGIT 3000
2
fblclp
fbloff
mixamp
I C Registers
– HSYNC as timing reference for clamping pulse gener-
ator
Fig. 2–4: Fast Blank Processing
– active video input to indicate valid video data and to
synchronize chroma multiplex for DIGIT 3000
2
Selectthe linear mixer or the nonlinear mixer via I C reg-
ister <12>SELLIN. If the nonlinear mixer is selected, a
dynamic delay control of the analog RGB/YUV input can
be chosen, to avoid edge artefacts of the RGB/YUV sig-
nal (e.g. shading), during transition time of Fast Blank
The FSY input and the AVI input are used to supply all
synchronization information necessary. Three basic
2
modes of operation can be selected via I C registers
<06>D2KIN, <17>D2KSYNC, <17>SYNCSIM, and
<17>P72BEN.
2
signal with the I C register <12>CTRLDLY.
In some applications, it is desired to disable the control
by the Fast Blank signal and to pass through the digital
YUVin path or the analog RGB/YUV path. This is pos-
sible by adequately programming the I C registers
<06>PASSYUV and <11>PASSRGB (Table 2–1).
In a DIGIT 2000 system environment, the CIP 3250A re-
ceives the synchronization information at the FSY input
via the DIGIT 2000 SKEW-protocol. The AVI Input may
be connected to ground GND or VDD (see section
2.14.).
2
Micronas
9
MICRONAS [ MICRONAS ]
