Hi, actually I'm using the Stratix IV GX Devkit (EP4SGX230KF40) and try to implement a communication using the HSMC- loobpack adapter on port HSMCA. The protocol I'm using is XAUI. I started with the ALTGX and ALTGX_RECONFIG Megafunctions and a pattern generator in conjunction with a pattern checker. This little testdesign works fine in some cases. Mostly the lanes on the receiver are mixed up compared to the transmitter even though the rx_channelaligned signal is set to '1' from the ALTGX function. There is an example desing on Alterawiki (http://www.alterawiki.com/wiki/xaui_design_example_1 (http://www.alterawiki.com/wiki/xaui_design_example_1) for Stratix V. This example use the XAUI_PHY and ALT_XCVR_RECONFIG megafunctions. I want to check if these functions solve my problem. Does any body know if the ALT_XCVR_RECONFIG are available for Stratix IV? Are there some ideas about the lane mix up? Jens

--- Quote Start --- actually I'm using the Stratix IV GX Devkit (EP4SGX230KF40) --- Quote End --- I have this kit. --- Quote Start --- and try to implement a communication using the HSMC- loobpack adapter on port HSMCA. The protocol I'm using is XAUI. I started with the ALTGX and ALTGX_RECONFIG Megafunctions and a pattern generator in conjunction with a pattern checker. This little testdesign works fine in some cases. Mostly the lanes on the receiver are mixed up compared to the transmitter even though the rx_channelaligned signal is set to '1' from the ALTGX function. --- Quote End --- I have not seen any lane assignment errors on this board. Do you mean that the data is scrambled from what you expect? Cheers, Dave

Hi Dave, the lanes are scrambled. If I send at tx_datain X"FFEEDDCCBBAA9988" the I receive at rx_dataout X"EEFFCCDDAABB8899". (see attached signal tap screenshots tx_datain.jpg and rx_dataout.jpg) In some cases the alignment is correct (rx_dataout2.jpg). Before sending the data I use two start packets. The transmission of these packets is always incorrect (see the screenshots). Which megafunction you are using? ALTGX and ALTGX_RECONFIG? What are your parameter settings? (if you want have a look at my settings, see params at the end of reply) Which clocks you re using? I use for XAUI Refclk the LVDS clock source at pin AA2 (156.25 MHz) For the dynamic reconfiguration circuit I'm using the freerunning clock clkin_50 at pin AC34. The data generator is clocked with the coreclockout from ALTGX block. How is your implementation of the reset controller for ALTGX_RECONFIG? My reset sequence is like in the Stratix IV Device Handbook Volume 2: Transceivers, page 4-8, figure 4-4. (see attached altgx_reset1.jpg and altgx_reset2.jpg) There just is one difference. In my case the busy signal is always '0'. How do you verfy the transmission? With external or internal loopback? p.s. I try using the XAUI_PHY (external reconfig is not required) like in the example for Stratix V. I didn't succeed. (tx_ready and rx_ready signals are always '0') Jens --------------------------------------- ALTGX settings --------------------------------------- General protocol: xaui nr of channels: 4 channel width: 16 effective data rate: 3125 clock freq.: 156.25 base data rate: 3125.0 PLL/ports train transceiver clock : enabled optional ports: enabled ports/calibration analog power: auto Rx analog static equalizer ctrl: disabled DC gain: 0 common mode voltage: 0.82 termination resistance: 100 ohm Tx analog transmitter buffer power: auto transmitter common mode voltage: 0.65 transmitter termination: 100 ohm next parameter all to 0 Reconfig sttings just offset cancellation is enabled

--- Quote Start --- the lanes are scrambled. If I send at tx_datain X"FFEEDDCCBBAA9988" the I receive at rx_dataout X"EEFFCCDDAABB8899". --- Quote End --- Your original description is ambiguous. The lanes (wires on the board) are not scrambled, the data from a lane is scrambled. Look at the pattern - what do you see? FFEE DDCC BBAA 9988 EEFF CCDD AABB 8899 Each 16-bit value has the bytes swapped. Now look in the Stratix IV user manual. You will find there is a FIFO that can cause this byte-swapping. You need to use the synchronization controls to align to a pattern; look at rx_byteorderalign and rx_enapatternalign, there is also a byte-reversal feature you can use (if you do not control the source of the data). However, I would have thought XAUI would have taken care of this for you, by initializing the link with sync codes. Cheers, Dave

Dave, you are right. The bytes are swapped. Also in some cases the alignment is not correct. I read in the transceiver section of Stratix IV hadbook that byte ordering is disabled in XAUI mode (refer figure 1-123, page 1-156). Furthermore the rx_enabyteord (together with rx_ byteorderalignstatus) signal is just used when byte ordering block is enabled. In XAUI mode I don't have access to these signals. Even if I had the possibility to restart byte ordering operation how should I know when it is to do? After each reset the byte order is random. In the attached screenshots you see also the misalignment. Affected are also the control signals. Transmit: control | 0xFF | 0x00 lane 3 | 0x0707 | 0xAD00 lane 2 | 0x0707 | 0x0000 lane 1 | 0x0707 | 0x0000 lane 0 | 0x0707 | 0x00AB Receive: control | 0xFF | 0x55 | 0xAA lane 3 | 0x0707 | 0x0007 | 0x07AD lane 2 | 0x0707 | 0x0007 | 0x0700 lane 1 | 0x0707 | 0x0007 | 0x0700 lane 0 | 0x0707 | 0xAB07 | 0x0700 (for more details see signal tap files in the zip archive). Dave, you have an example with XAUI running on the Devkit and loopback adapter? I could compare it with my implementation. Jens Jens

Hi Jens, --- Quote Start --- Dave, you are right. The bytes are swapped. Also in some cases the alignment is not correct. --- Quote End --- Ok, so this is a XAUI synchronization issue then. I have not used the XAUI core. --- Quote Start --- After each reset the byte order is random. In the attached screenshots you see also the misalignment. --- Quote End --- I'd recommend putting a Modelsim simulation together. Its a lot easier to probe signals and change things there. --- Quote Start --- Dave, do you have an example with XAUI running on the Devkit and loopback adapter? I could compare it with my implementation. --- Quote End --- I'm sorry, but I do not. Perhaps someone more familiar with the operation of the XAUI core can comment on how the link is supposed to be synchronized. Cheers, Dave

XAUI Phy in Stratix IV GX | Altera Community

12 Replies

Altera_Forum
Honored Contributor
12 years ago
Thank you for all the support and help!

On the 10Gbps MAC Megacore User Guide (page 148), it is written that the Recofiguration is not necessary for Stratix IV GX Devices.

Unfortunately I don't have any SFP+ interfaces available here (my supervisor haven't bought it yet), that's why I'm trying to loopback the XAUI interface to test it. Isn't there any way of doing this with the HSMC Loopback Module?

Thank you once more!

--- Quote Start ---
Yes, you need the reconfiguration controller because the offset cancellation must be done. Look at my attached screenshots.
They show the settings for the LPMs, which I use actually on a custom hardware. For the devkit it should be the same. The analog options in
XAUI Phy may vary.

xaui_lpms.jpg show the connection between reconfig controller and phy. The signal reconfig_fromgxb is splitted between the 2 phys. (described in
Stratix IV Device Handbook Volume 2: Transceivers, Feb. 2011, p. 5-77)

reconfig_clk.jpg shows the constraints for the clock to the reconfig controller. Use an appropriate clock on the devkit.

The connection from xgmii_rx_clk to xgmii_tx_clk is correct. I use this clock to drive the control logic for send and receive data over the XAUI channels.
I do not use a MAC (10GE) just the low level XAUI protocol.

best regards
Jens
--- Quote End ---
Altera_Forum
Honored Contributor
12 years ago
Hello again.

I have tried to run even the original Altera projects (i.e. an638) and had no success. As always, xgmii_rx_clk didn't work, which made me think that could perhaps be some type of hardware fault.

So I've switched my project to a Stratix V and it worked fine with the loopback!

So again, thanks for everyone who help me!

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XAUI Phy in Stratix IV GX

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