GTS Transceiver PHY User Guide

ID 817660
Date 10/07/2024
Public
Document Table of Contents

2.6.1. Reference Clock Network

Thee ae two types of clock lies i the efeece clock etwok; local ad egioal efeece clock lies. Fo evey GTS tasceive bak, thee ae two idepedet diffeetial efeece clock iput pis. The followig figue shows the efeece clock etwok ad efeece clock iput pis fo GTS tasceive baks.
Figue 24. Refeece Clock Netwok fo Devices with Multiple GTS Tasceive Baks o a Side

The fist is the local efeece clock, which ca each ay chael i the same GTS tasceive bak ad the system PLL. This local efeece clock pi is bi-diectioal, except o devices with a sigle GTS tasceive bak o a side, whee it seves as a iput oly efeece clock pi. You ca cofigue this bi-diectioal pi as a output fo the CDR ecoveed clock fom ay of the fou chaels i the GTS tasceive bak. I oe of the tasceive baks of the device, thee is a additioal output oly pi of this type. The bak locatio whee this output oly CDR ecoveed clock esides vaies acoss the diffeet device vaiats. You ca fid the bak locatio of the CDR ecoveed clock output pis i the device piout files.

The secod available iput efeece clock pi is the egioal efeece clock. This efeece clock ca be used to feed all the chaels ad system PLLs i the two closest GTS tasceive baks above o below its ow bak. Fo example, i a fou GTS tasceive bak device, the egioal efeece clock pi i bak 0 ca be used i bak 1 ad bak 2 as well. Howeve, bak 3 is out of each of the egioal efeece clock pi i bak 0.

Additioally, the system PLL ca also get its iput efeece clock fom outside the GTS tasceive bak. Adjacet to the GTS tasceive bak, thee is a high voltage IO (HVIO) bak. Thee ae 4 sigle-eded iput efeece clock pis i the HVIO bak that ca be used by the system PLL as a secoday optio fo the efeece clock iput souce.
Table 13.  Refeece Clock Souce Compaiso
Desciptio Local Refeece Clock Regioal Refeece Clock HVIO Refeece Clock
Used by PMA ad system PLL PMA ad system PLL System PLL
Reach All PMA chaels ad system PLL withi a GTS tasceive bak All PMA chaels ad system PLL i the two closest GTS tasceive baks above o below its ow bak. All system PLLs o the same side of device
Recoveed clock output Available Not available Not available
Iput/Output Bi-diectioal, eithe:
  • Iput efeece clock
  • Output ecoveed clock
Iput oly Iput oly
Pi locatio GTS Tasceive bak GTS Tasceive bak HVIO5B o HVIO6A bak
Sigal type Diffeetial Diffeetial Sigle eded
The PMA (TX PLL ad CDR) efeece clock souces ae:
  • Local efeece clock iput
  • Regioal efeece clock iput (fom same GTS tasceive bak o fom the eighboig GTS tasceive baks alog the same side of the device)
System PLL efeece clock souces ae:
  • Local efeece clock iput
  • Regioal efeece clock iput (fom same GTS tasceive bak o fom the eighboig GTS tasceive baks alog the same side of the device)
  • Dual pupose sigle eded pis (up to fou) fom HVIO5B o HVIO6A baks.

The CDR i ay oe of the fou PMA chaels withi the GTS tasceive bak ca sed the ecoveed clock exteally, fo example to feed a exteal jitte cleae. The output ecoveed clock is fed exteally though the bi-diectioal local efeece clock pi. The iput efeece clock is ot available whe this pi is beig used fo the ecoveed clock. I this sceaio, the efeece clock ca come fom ay of the egioal efeece clock lies.

I additio to the bidiectioal local efeece clock pi, thee is oe additioal dedicated CDR clock out pi i oe of the GTS tasceive baks. You ca use this pi to dive out the ecoveed clock. You must use this pi if you ae plaig to migate to the smallest device vaiat i the futue. This is because devices with a sigle GTS tasceive bak o a side have a slightly diffeet clock etwok. Refe to Sigle GTS Tasceive Bak Device fo moe ifomatio.

If you pla to migate you desig to Agilex™ 5 D-Seies FPGAs, efe to the Device Migatio Guidelies: Agilex™ 5 FPGAs ad SoCs D-Seies (Itel RDC item #827018).