AXI Bridge for PCI Express v2.4
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PG055 June 4, 2014
Chapter 2:
Product Specification
configured Max Payload Size setting, which are passed to the Integrated Block for PCI
Express.
A second remote AXI master initiated write request write address and qualifiers can then be
captured and the associated write data queued, pending the completion of the previous
write TLP transfer to the core. The resulting AXI Slave Bridge write pipeline is two-deep.
When a remote AXI master initiates a read transaction to the Slave Bridge, the read address
and qualifiers are captured and a MemRd request TLP is passed to the core and a
completion timeout timer is started. Completions received through the core are correlated
with pending read requests and read data is returned to the AXI master. The Slave bridge is
capable of handling up to eight memory mapped AXI4 read requests with pending
completions.
The Master Bridge processes both PCIe MemWr and MemRd request TLPs received from the
integrated block for PCI Express and provides a means to translate addresses that are
mapped within the address for PCIe domain to the memory mapped AXI4 address domain.
Each PCIe MemWr request TLP header is used to create an address and qualifiers for the
memory mapped AXI4 bus and the associated write data is passed to the addressed
memory mapped AXI4 Slave. The Master Bridge can support up to four active PCIe MemWr
request TLPs.
Each PCIe MemRd request TLP header is used to create an address and qualifiers for the
memory-mapped AXI4 bus. Read data is collected from the addressed memory mapped
AXI4 Slave and used to generate completion TLPs which are then passed to the integrated
block for PCI Express. The Master bridge can handle up to four read requests with pending
completions for improved AXI4 pipelining performance.
The instantiated AXI4-Stream Enhanced PCIe block contains submodules including the
Requester/Completer interfaces to the AXI bridge and the Register block. The Register
block contains the status, control, interrupt registers, and the AXI4-Lite interface.
Standards
The AXI Bridge for PCIe core is compliant with the
ARM® AMBA® AXI4 Protocol
Specification
PCI Express Base Specification v2.0