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6,877 Views
Registered: ‎06-23-2011

Virtex 6 GTX with SATA OOB , COMWAKE not detected

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I'm using an ML605 board with FMC XM104 for SATA. For PHY initialization I'm using the virtex 5 GTP app note as a reference (XAPP870). I first created a wrapper for the V6 GTX transceivers using the SATA protocol template in coregen. I had initial problems with the PLL lock signal not getting asserted on reset (RXPLLLKDET) and found that the clock multiplier on the FMC card needs to be enabled and programmed using IIC. Right now I'm using a clock from the FMC (GBTCLK1_M2C) which does not go through the clock multiplier (Si5368). Instead, it connects directly through the J1 HPC connector. This differential clock is passed trough an IBUFDS_GTXE1 component which generates the MGTREFCLK. The transceiver generates the TXOUTCLK which is given to an MMCM to generate TXUSRCLCK and TXUSRCLK2 for the GTX.

I'm trying to send OOB signals by asserting the TXCOMINIT and TXCOMWAKE signals. ( This is a little different from the GTPs where the TXCOMTYPE and TXCOMSTART signals are asserted). I can detect the COMINIT signals from the device (as well as the COMFINISH ) but fail to detect the COMWAKE signals. Has anyone tried this? Any suggestions would be appreciated. 

 

Thanks

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7,459 Views
Registered: ‎06-23-2011

Re: Virtex 6 GTX with SATA OOB , COMWAKE not detected

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It works now !!! COMWAKE is detected.  The issue was that the transmitter differential voltage swing parameter (TXDIFFCTRL) is a user configurable parameter and the coregen sata template for the GTXs leaves it floating. Due to this, it was driving the TX signals at a default value of 110mV. I changed this to 810mV and OOB signals are sent and detected !

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Moderator
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Registered: ‎02-16-2010

Re: Virtex 6 GTX with SATA OOB , COMWAKE not detected

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How is TXELECIDLE driven? It is required to be driven HIGH for generating SATA/SAS OOB COM signaling
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6,848 Views
Registered: ‎06-23-2011

Re: Virtex 6 GTX with SATA OOB , COMWAKE not detected

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I'm driving TXELECIDLE high as required by SATA OOB COM signaling

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7,460 Views
Registered: ‎06-23-2011

Re: Virtex 6 GTX with SATA OOB , COMWAKE not detected

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It works now !!! COMWAKE is detected.  The issue was that the transmitter differential voltage swing parameter (TXDIFFCTRL) is a user configurable parameter and the coregen sata template for the GTXs leaves it floating. Due to this, it was driving the TX signals at a default value of 110mV. I changed this to 810mV and OOB signals are sent and detected !

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6,773 Views
Registered: ‎07-14-2011

Re: Virtex 6 GTX with SATA OOB , COMWAKE not detected

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We are also facing the same problem in our hardware.  I would like to know, how long the COMINIT / COMRESET signal is asserted.  Also pls mention, if any other changes have to be done while generating the core using GTX wizard.

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Teacher
Teacher
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Registered: ‎09-09-2010

Re: Virtex 6 GTX with SATA OOB , COMWAKE not detected

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"I would like to know, how long the COMINIT / COMRESET signal is asserted."
Read The Fine Specification, or measure it on some hardware with an oscilloscope.

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"If it don't work in simulation, it won't work on the board."
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6,761 Views
Registered: ‎07-14-2011

Re: Virtex 6 GTX with SATA OOB , COMWAKE not detected

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Initially, i was asserting cominit for 4us as per XAPP870.pdf(For virtex-5) but i didnt receive comwakedet signal. Later, i tried by asserting cominit for one clk period(75Mhz) even then i dint receive. so how lond this cominit has to be asserted?

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