HDMP-1012 Datasheet, PDF (30/42 Pages) Agilent(Hewlett-Packard) – 4Low Cost Gigabit Rate Transmit/Receive Chip Set

FDIS
SIN
STRBOUT
FREQ
0
1
PHASE
CLOCK GEN
DIV N
BCLK
DIV0 DIV1
0
VCO
1
TCLK
TCLKSEL
PH1
FILTER
Figure 14. HDMP-1014 (Rx) Phase-Locked Loop.
the frequency detector to align its
internal clock with the rising edge
of FF0/FF1. Once frequency lock
is accomplished, FDIS can be set
to 1, then the PLL uses only the
phase detector for
synchronization adjustment and
the Rx is ready to receive data.
Due to the narrow frequency
acquisition range of the phase
detector, the frequency detector
is used for internal frequency
acquisition. The frequency
detector, however, can only work
with FF0 and FF1 and it is
necessary for the PLL selecting
the phase detector (by setting
FDIS=1) before receiving any
random data.
The output of the phase-
frequency detector is externally
available through pin PHI. An
external clock source can also be
used (through pin TCLK) by
setting TCLKSEL=1. To broaden
the usable frequency range of the
chip, there is a programmable
divider before the clock
generator. The VCO or TCLK
frequency can be divided by 1, 2,
4, 8 by setting DIV1, DIV0 = 00,
01, 10, 11 (see Operating Rate
Tables).
HDMP-1014 (Rx)
Decoding
In Figure 5, the frame
demultiplexer de-serializes the
recovered serial data from the
Input Sampler, and outputs the
resulting parallel data one frame
at a time. Every frame is
composed of a 16-bit or 20-bit
Data Field (D-Field) and a 4-bit
Control Field (C-Field). The C-
Field, C0-C3, together with the
two center bits of the D-Field (D9
and D10 for 20 bit mode, D7 and
D8 for 16 bit mode) are then
decoded by the C-Field decoder to
determine the content of the
frame. The D-Field decoder is
controlled by the outputs of the C-
Field decoder. If an inverted Data
Word or Control Word is
detected, the D-Field decoder will
automatically invert the D-Field
data. If a Control Frame is
detected, the D-Field decoder will
shift the bottom half of the D-
Field so that the outputs are at
pin D0 - D17 (if M20SEL =1) or
at pin D0 - D13 (if M20SEL =0).
A data Frame is detected by the
receiver when DAV = 1. A control
Frame is detected by the receiver
if CAV = 1. A Fill Frame is
detected by the receiver if DAV =
0 and CAV = 0.
The C-Field decoder will set iERR
= 1 when it detects an error. The
internal error bit (iERR) is
combined with the internal flag
bit (iFLAG) and the flag-bit mode-
select signal (FLAGSEL) to
produce the externally available
error bit (ERROR) and flag
(FLAG) bits. If FLAGSEL=1, the
FLAG can be used as an extra
data bit
• ERROR=iERR.
• FLAG=iFLAG.
• If a Fill Frame is detected, then
FLAG=0.
• If a Control Frame is detected,
FLAG should be ignored.
If FLAGSEL=0, the serial input is
assumed to consist of alternating
602