HDMP-0422 Datasheet, PDF (1/14 Pages) Agilent(Hewlett-Packard) – Single Port Bypass Circuit with CDR & Data Valid Detection Capability for Fibre Channel Arbitrated Loops

Agilent HDMP-0422
Single Port Bypass Circuit with CDR &
Data Valid Detection Capability
for Fibre Channel Arbitrated Loops
Data Sheet
Description
The HDMP-0422 is a Single Port
Bypass Circuit (PBC) with Clock
and Data Recovery (CDR)
capability included. This integrated
circuit provides a low-cost, low-
power physical-layer solution for
Fibre Channel Arbitrated Loop
(FC-AL) disk array configurations.
By using a PBC such as the HDMP-
0422, hard disks may be pulled out
or swapped while other disks in the
array are available to the system.
A PBC consists of multiple 2:1
multiplexers daisy chained along
with a CDR. Each port has two
modes of operation: “disk in loop”
and “disk bypassed.” When the
“disk in loop” mode is selected, the
loop goes into and out of the disk
drive at that port. For example,
data goes from the HDMP-0422’s
TO_NODE[n]± differential output
pins to the Disk Drive Transceiver
IC’s (e.g. an HDMP-1636A) Rx
differential input pins. Data from
the Disk Drive Transceiver IC’s Tx
differential outputs goes to the
HDMP-0422’s FM_NODE[n]±
differential input pins. Figures 2
and 3 show connection diagrams
for disk drive array applications.
When the “disk bypassed” mode is
selected, the disk drive is either
absent or non-functional and the
loop bypasses the hard disk.
The “disk bypassed” mode is
enabled by pulling the BYPASS[n]-
pin low. Leave BYPASS[n]-
floating to enable the “disk in
loop” mode. HDMP-0422s may be
cascaded with other members of
the HDMP-04XX/HDMP-05XX
family through the appropriate
FM_NODE[n]± and
TO_NODE[n]± pins to
accommodate any number of hard
disks (see Figure 4). The unused
cells in the HDMP-0422 may be
bypassed by using pulldown
resistors on the BYPASS[n]- pins
for these cells.
Features
• Supports 1.0625 GBd Fibre
Channel operation
• Supports 1.25 GBd Gigabit
Ethernet (GE) operation
• Single PBC/CDR in one package
• CDR location determined by
choice of cable input/output
• Amplitude valid and data valid
detection (Fibre channel rate only)
on FM_NODE[0] input
• Equalizers on all inputs
• High-speed LVPECL I/O
• Buffered Line Logic (BLL) outputs
(no external bias resistors
required)
• 0.46 W typical power at
VCC = 3.3 V
• 24 Pin, low-cost SSOP package
Applications
• RAID, JBOD, BTS cabinets
• One 2:1 muxes
• One 1:2 buffers
• 1 ≥ N Gigabit serial buffer
• N ≥ 1 Gigabit serial mux
An HDMP-0422 may also be used
as two 1:1 buffers, one with a CDR
and one without. For example, an
HDMP-0422 may be placed in
front of a CMOS ASIC to clean the
jitter of the outgoing signal (CDR
path) and to better read the
incoming signal (non-CDR paths).
In addition, the HDMP-0422 may
be configured as one 2:1
multiplexers or as one 1:2 buffers.
HDMP-0422
CAUTION: As with all semiconductor ICs, it is advised that normal static precautionsb be taken in
the handling and assembly of this component to prevent damage and/or degradation which may be
induced by electrostatic discharge (ESD).