Figure 7–7. endian conversion – Altera 10-Gbps Ethernet MAC MegaCore Function User Manual
Page 77
7–10
Chapter 7: Functional Description
Transmit Datapath
10-Gbps Ethernet MAC MegaCore Function User Guide
February 2014
Altera Corporation
shows the timing for the transmit frames on the Avalon-ST interface and
the SDR XGMII. By comparing the data value in D3, the SDR XGMII performs endian
conversion by transmitting the frames from the least significant byte.
Figure 7–7. Endian Conversion
Note to
:
(1) In the preamble passthrough mode, the MAC TX frame starts with a 1-byte START and a 7-byte client-defined
preamble.
tx_clk_clk
xgmii_tx_data[71]
xgmii_tx_data[70:63]
xgmii_tx_data[62]
xgmii_tx_data[61:54]
xgmii_tx_data[53]
xgmii_tx_data[52:45]
xgmii_tx_data[44]
xgmii_tx_data[43:36]
xgmii_tx_data[35]
xgmii_tx_data[34:27]
xgmii_tx_data[26]
xgmii_tx_data[25:18]
xgmii_tx_data[17]
xgmii_tx_data[16:9]
xgmii_tx_data[8]
xgmii_tx_data[7:0]
D5
(1)
CC
01
09
11
19
21
29
F4
55
(1)
EE
00
08
10
18
20
28
0A
55
(1)
EE
2E
07
0F
17
1F
27
B3
55
(1)
AA
00
06
0E
16
1E
26
4E
55
(1)
CC
EE
05
0D
15
1D
25
2D
55
(1)
88
AA
04
0C
14
1C
24
2C
55
(1)
CC
03
0B
13
1B
23
2B
FB
EE
88
02
0A
12
1A
22
2A
FD
tx_clk_clk
avalon_st_tx_startofpacket
avalon_st_tx_endofpacket
avalon_st_tx_valid
avalon_st_tx_ready
avalon_st_tx_data [63:0]
avalon_st_tx_empty [2:0]
avalon_st_tx_error
0
4
D1: EECC88CCAAEEEECC
D2: 88CCAAEE002E0001
D3: 0203040506070809
D4: 0A0B0C0D0E0F1011
D5: 1213141516171819
D6: 1A1B1C1D1E1F2021
D7: 2223242526272829
D8: 2A2B2C2D00000000
D1
D2
D3
D4
D5
D6
D7
D8
Data value: