VITESSE
SEMICONDUCTOR CORPORATION
500 Mb/s Video
Shift Register IC
Preliminary Datasheet
VSC6424
HBLANK
or
VBLANK
must be driven low for at least one clock cycle two clock cycles before the desired
point of blanking. See Figure 6 for a timing illustration of this function.
Retimer
The chip also contains a retimer function. This function works in
DEMUX
mode. The
RETIME
signal is
routed to
DOUT<7>
through a flip-flop. The flip-flop is internally clocked by the low speed ECL output clock
(CLKE). This function is depicted in the detailed block diagram (Figure 3) below. See Figure 5 for a timing
illustration.
Figure 2: Multiplexer Detailed Block Diagram
O
EN
M D
O E
AEN/RETIME
A<0:4>
HBLANK
VBLANK
CLKE
Retimer
DOUT<7>
S<0:2>
7
40
8
MUX
Output
Latch
8
DOUT<0:6>
High
Speed
Interface
(ECL)
O
PS
C
LK
CLKOUT
Termination
It is recommended to leave all unused ECL outputs floating. It is recommended that unused ECL inputs be
terminated low (-2V supply). Refer to the following table recommended input termination for all levels.
Table 4: Input Termination Recommendations
Type
ECL
ECL
TTL
TTL
State
High
Low
High
Low
Input
ground via a diode
-2V supply
+3.3V supply
Ground
Page 6
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VITESSE
SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
G52236-0, Rev 3.0
7/13/99
VITESSE [ VITESSE SEMICONDUCTOR CORPORATION ]
