Altera Stratix V Avalon-ST - Manual (Page 73)

Signal Direction Description
words that contain data, resulting in the following encodings for
the 128-and 256-bit interfaces:
128-Bit interface:
tx_st_empty
= 0,
tx_st_data[127:0]
contains
valid data
tx_st_empty
= 1,
tx_st_data[63:0]
contains valid
data
256-bit interface:
tx_st_empty
= 0,
tx_st_data[255:0]
contains
valid data
tx_ st_empty
= 1,
tx_st_data[191:0]
contains valid
data
tx_st_empty
= 2,
tx_st_data[127:0]
contains valid
data
tx_st_empty
= 3,
tx_st_data[63:0]
contains valid data
For 256-bit data, when you turn on Enable multiple packets per
cycle, the following correspondences apply:
• bit 1 applies to the eop occurring in rx_st_data[255:128]
• bit 0 applies to the eop occurring in rx_st_data[127:0]
When the TLP ends in the lower 128bits, the following equations
apply:
•
tx_st_eop[0]=1 & tx_st_empty[0]=0
,
tx_st_
data[127:0]
contains valid data
•
tx_st_eop[0]=1 & tx_st_empty[0]=1
,
tx_st_data[63:0]
contains valid data,
tx_st_data[127:64]
is empty
When TLP ends in the upper 128bits, the following equations
apply:
•
tx_st_eop[1]=1 & tx_st_empty[1]=0
,
tx_st_
data[255:128]
contains valid data
•
tx_st_eop[1]=1 & tx_st_empty[1]=1
,
tx_st_
data[191:128]
contains valid data,
tx_st_data[255:192]
is
empty
UG-01097_avst
2014.12.15
Avalon-ST TX Interface 5-21
Interfaces and Signal Descriptions Altera Corporation
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