Root port design example – Altera Arria V Avalon-ST User Manual
Page 191
Offset in DMA Control
Registers (BAR2)
Value
Description
DW1
0x14
0
BFM shared memory
upper address value
DW2
0x18
0x900
BFM shared memory
lower address value
DW3
0x1c
2
Last descriptor written
After writing the last dword of the Descriptor header (DW3), the DMA read starts the three
subsequent data transfers.
3. Waits for the DMA read completion by polling the BFM shared memory location 0x90c, where the
DMA read engine is updating the value of the number of completed descriptors. Calls the procedures
rcmem_poll
and
msi_poll
to determine when the DMA read transfers have completed.
Root Port Design Example
The design example includes the following primary components:
• Root Port variation (
• Avalon-ST Interfaces (altpcietb_bfm_vc_intf_ast)—handles the transfer of TLP requests and
completions to and from the Arria V Hard IP for PCI Express variation using the Avalon-ST interface.
• Root Port BFM tasks—contains the high-level tasks called by the test driver, low-level tasks that
request PCI Express transfers from altpcietb_bfm_vc_intf_ast, the Root Port memory space, and
simulation functions such as displaying messages and stopping simulation.
• Test Driver (altpcietb_bfm_driver_rp.v)—the chaining DMA Endpoint test driver which configures
the Root Port and Endpoint for DMA transfer and checks for the successful transfer of data. Refer to
the Test Driver Modulefor a detailed description.
2014.12.15
Root Port Design Example
16-21
Testbench and Design Example
Altera Corporation