64 SBC329 3U VPX Single Board Computer
Publication No. SBC329-HRM/1
5.15 Mezzanine Site
The SBC329 has one mezzanine site that supports suitably compliant XMCs
(including support for front-panel I/O).
The site provides Jn5 and Jn6 connectors. J15 provides a Gen2 capable x8 PCIe link to
the PCIe Switch. J16 is used to route XMC I/O to the backplane, depending on build
options (see the I/O Routing section below).
The XMC VPWR supply is provided by a direct connection to VS3 (+5V), so only
XMCs that s5V VPWR operation are supported on the SBC329.
The System Management pins of the XMC site are
connected to a dedicated I
2
C
interface on the BMM. The geographic address of XMC site is configured to 000
b
.
Software can determine the presence of an XMC in the site from the FPGA.
5.15.1
XMC Connectors
The SBC329 is fitted with standard VITA 42 XMC compatible connectors. However,
there is an option to upgrade to VITA 61 connectors, which offer a superior
bandwidth and increased reliability. See the
5.15.2
I/O Routing
Rear I/O tracking is
provided from the J16 connector to the rear VPX connectors in
accordance with VITA 46.9. Depending on build variant, the following
configurations are available:
Table 5-14 XMC I/O Routing Availability
Build Variant
I/O Available
VITA46.9 Pin Mapping Pattern
SBC329-xxxxxXxxx or
SBC329-xxxxxYxxx
64 (24 single-ended, 20 differential pairs) P2w1-X24s+X8d+X12d
SBC329-xxxxx1xxx or
SBC329-xxxxx2xxx
24 (12 differential pairs)
P2w11-X12d
Software can determine the option selected from the
All single-ended signals are routed with a single-ended impe
dance of 45 Ω and are
length matched to 0.5 inches. All differential pairs are routed with a differential
impedance of 85 Ω. All pairs (inter
-pair) within each signal group (i.e. X8d and
X12d) are length matched to within 0.5 inches. Each signal within a pair (intra-pair)
is length matched to 10 thousandths of an inch.