48 PPC11A 6U VME Single Board Computer
Publication No. PPC11A-HRM/1
4.18
Mezzanines
4.18.1 PMC/XMC Sites
The PPC11A has two mezzanine sites that both support IEEE P1386.1-compliant
PMCs or VITA42.3-compliant XMCs (including support for front-panel I/O). The two
mezzanine sites are spaced to allow fitting of a double-width PMC/XMC if required.
The PCIe Switch provides a PCIe Gen 2, x4 link for each PMC site bridge and a
dedicated PCIe Gen 2, x8 link to each XMC site.
The presence of a PMC/XMC in a site is shown in the appropriate XMC/PMC Site
Status Register (
4.18.2 PMCs
Each PMC site has Jn1, Jn2, Jn3 and Jn4 connectors to provide a 64-bit PCI bus
capable of PCI-X operation at frequencies of up to 133 MHz. The interface is also
5V-tolerant and supports the use of 5V PMCs at 33 MHz signaling rate only.
CAUTION
Ensure that the PMC1 and PMC2 5 V VIO selections are configured for the requirements of any
corresponding PMCs fitted. Damage to the PMC may otherwise result.
Each PCI bus is connected to a Pericom PI7C9X130 PCI-Express to PCI Bridge, which
provides clocks and arbitration for the bus. The speed of the bus is based on the
capability of the PMC, and is determined by the bridge during reset. The current
operating frequency of each bus may be ascertained by reading registers within the
appropriate bridge.
The PMC_PRESENT~ signal from each site is used to hold the respective PCIe to PCI
bridge in reset if detected high (PMC site empty) to conserve power. A pair of red
LEDs, mounted on the back of the PPC11A, indicates the reset status of each bridge;
when in reset, the LED is lit. A register
in the FPGA can be used to control the reset
line to each bridge, in software, as required.
The PMC site supports Processor PMCs (as defined by VITA32-2002) operating in
non-Monarch mode only. This includes support for PMCs with two PCI masters.
Each PMC site has a dedicated PCI bus, so fitting a PMC that runs at a lower
frequency does not limit the other PMC or the performance of other PPC11A
functions.
Both PMC sites support the PMC EREADY signal. This can be used by a ‘slow to
initialize’ PMC to delay PCI enumeration until the PMC’s PCI interface is ready to
participate
TIP
This may be useful if the PCI interface is part of a slow loading FPGA design.
Содержание PPC11A
Страница 1: ...Hardware Reference Manual PPC11A 6U VME Single Board Computer Edition 1 Publication No PPC11A HRM 1 ...
Страница 27: ...Publication No PPC11A HRM 1 Functional Description 27 Figure 4 2 Block Diagram T2081 ...
Страница 113: ...Publication No PPC11A HRM 1 Connectors 113 Figure 6 2 Rear Connector Position ...