6–24
Chapter 6: IP Core Interfaces
Avalon-ST TX Interface
Stratix V Hard IP for PCI Express
June 2012
Altera Corporation
shows the mapping of 128-bit Avalon-ST TX packets to PCI Express TLPs
for a four dword header TLP with qword aligned data.
shows the mapping of 128-bit Avalon-ST TX packets to PCI Express TLPs
for a four dword header TLP with non-qword aligned addresses. In this example,
tx_st_empty
is low because the data ends in the upper 64 bits of
tx_st_data
.
Figure 6–26. 128-Bit Avalon-ST tx_st_data Cycle Definition for 4-Dword Header TLP with Qword Aligned Address
pld_clk
tx_st_data[127:96]
tx_st_data[95:64]
tx_st_data[63:32]
tx_st_data[31:0]
tx_st_sop
tx_st_eop
tx_st_empty
Header 3
Data 3
Header 2
Data 2
Header 1
Data 1
Header 0
Data 0
Data 4
Figure 6–27. 128-Bit Avalon-ST tx_st_data Cycle Definition for 4-Dword Header TLP with non-Qword Aligned Address
Header 3
Data 2
Header 2
Data 1
Data n
Header 1
Data 0
Data n-1
Header 0
Data n-2
pld_clk
tx_st_valid
tx_st_data[127:96]
tx_st_data[95:64]
tx_st_data[63:32]
tx_st_data[31:0]
tx_st_sop
tx_st_eop
tx_st_empty