Frame Demux and Byte Sync
characters must not be
transmitted in consecutive bytes
to allow the receiver byte clocks
to maintain their proper
The FRAME DEMUX AND BYTE
SYNC block is responsible for
restoring the 10-bit parallel
recovered frequencies.
data from the high speed serial bit
stream. This block is also
Output Drivers
responsible for recognizing the
comma character (or a K28.5
character) of positive disparity
(0011111xxx). When recognized,
the FRAME DEMUX AND BYTE
SYNC block works with the RX
PLL/CLOCK RECOVERY block
to properly align the receive byte
clocks to the parallel data. When a
comma character is detected and
realignment of the receiver byte
clocks (RBC1/RBC0) is necessary,
these clocks are stretched, not
slivered, to the next possible
correct alignment position. These
clocks will be fully aligned by the
start of the second 2-byte ordered
set. The second comma character
received shall be aligned with the
rising edge of RBC1. As per the
8B/10B encoding scheme, comma
The OUTPUT DRIVERS present
the 10-bit parallel recovered data
byte properly aligned to the
receive byte clocks (RBC1/RBC0),
as shown in Figure 5. These
output data buffers provide TTL
compatible signals.
Signal Detect
The SIGNAL DETECT block
examines the differential
amplitude of the inputs DINB.
When this input signal is too
small, it outputs a logic 0 at
SIG_DET (refer to SIG_DET pin
definition for detection
thresholds). When the signal at
DINB is of a valid amplitude,
SIG_DET is set to logic 1.
HDMP-1638G (Transmitter Section) Timing Characteristics
T = 0°C to +70°C, V = 3.15 V to 3.45 V
A
CC
Symbol
Parameter
Units
nsec
nsec
nsec
bits
Min.
1.5
Typ.
Max.
t
t
Setup Time
Hold Time
setup
hold
1.0
[1]
t_txlat
Transmitter Latency
3.5
4.4
Note:
1. The transmitter latency, as shown in Figure 4, is defined as the time between the latching in of
the parallel data word (as triggered by the rising edge of the transmit byte clock, REFCLK) and
the transmission of the first serial bit of that parallel word at either output pair (defined by the
rising edge of the first bit transmitted).
4
PMC-Sierra, Inc. - Not Recommended for New Designs
PMC [ PMC-SIERRA, INC ]
