Altera IP Compiler for PCI Express - Manual (Page 250)

15–18 Chapter 15: Testbench and Design Example
Test Driver Module
IP Compiler for PCI Express User Guide August 2014 Altera Corporation
Table 15–11 shows the layout of the descriptor fields following the descriptor header.
Each descriptor provides the hardware information on one DMA transfer. Table 15–13
describes each descriptor field.
Test Driver Module
The BFM driver module generated by the parameter editor during the generate step is
configured to test the chaining DMA example endpoint design. The BFM driver
module configures the endpoint configuration space registers and then tests the
example endpoint chaining DMA channel.
For an endpoint VHDL version of this file, see:
<variation_name>_examples/chaining_dma/testbench/
altpcietb_bfm_driver_chaining.vhd
For an endpoint Verilog HDL file, see:
<
variation_name>_examples/chaining_dma/testbench/
altpcietb_bfm_driver_chaining.v
Table 15–11. Chaining DMA Descriptor Format Map
3122 21 16 150
Reserved Control Fields (refer to Table 15–12 ) DMA Length
Endpoint Address
RC Address Upper DWORD
RC Address Lower DWORD
Table 15–12. Chaining DMA Descriptor Format Map (Control Fields)
2118 17 16
Reserved EPLAST_ENA MSI
Table 15–13. Chaining DMA Descriptor Fields
Descriptor Field
Endpoint
Access
RC Access Description
Endpoint Address R R/W
A 32-bit field that specifies the base address of the memory transfer on the
endpoint site.
RC Address
Upper DWORD
R R/W Specifies the upper base address of the memory transfer on the RC site.
RC Address
Lower DWORD
R R/W Specifies the lower base address of the memory transfer on the RC site.
DMA Length R R/W Specifies the number of DMA DWORDs to transfer.
EPLAST_ENA R R/W
This bit is OR’d with the EPLAST_ENA bit of the control register. When
EPLAST_ENA
is set, the endpoint DMA module updates the EPLAST field of
the descriptor table with the number of the last completed descriptor, in the
form <0 – n>. (Refer to
Table 15–10 .)
MSI_ENA R R/W
This bit is OR’d with the MSI bit of the descriptor header. When this bit is set
the endpoint DMA module sends an interrupt when the descriptor is
completed.