Xilinx Boards and Kits

[cxyzkaka]

HI, 

I  am using ML605 ‘ FMC-LPC to drive a chip which is on another pcb ，but  the chip need 3.3V and 1.5V . I am going to use 3.3V  voltage on LPC.    I  Want to supply  1.5V from ML605. I  want to   know  if it works? Whether it has any damage to ML605?

thanks

[cxyzkaka]

ML605 has many  voltage such as 12V  3.3V  1.5V 2.5V..,I mean if i can use a fly line from FMC  to connect  to 1.5V on ml605.

thanks

[cxyzkaka]

 I Must Add  a picture ，IT is a switch Circuit diagram，I want  to  use its 1.5v voltage。 The chip need 700MA  current，Whether  the FPGA can  bear it？  

[mcgett]

You must use compatible IO standards for correct functionality and to avoid damage.

The pushbutton circuit that you posted is connected to 1.5V because it is connected to a bank on the FPGA with a VCCO of 1.5V.

The FMC interfaces on the ML605 are connected to banks with a VCCO of 2.5V so your FMC IO must use 2.5V.  If this is not compatible with other devies on the FMC then you must use level translators.

[cxyzkaka]

Now  I am confused。

the chip need 3.3V for I/O which are connect to FMC,and 1.5V for core. You mean FMC IO must use 2.5V. there are 12V ,2.5V,3.3V voltage on the FMC. I only have to use 2.5V?    whether 3.3V can be used ?

For the power supply ,Can you give some advices?

thanks very much!

[mcgett]

> Now  I am confused

It should be very obvious that connections between devices must have matching specifications in order to work.

> the chip need 3.3V for I/O which are connect to FMC,and 1.5V for core.

Ok, this is the specification for the device on the FMC module that you are trying to build

> You mean FMC IO must use 2.5V

Yes, the ML605 uses IO with a VCCO of 2.5V

> there are 12V ,2.5V,3.3V voltage on the FMC. I only have to use 2.5V?    whether 3.3V can be used ?

Yes, the FMC connector does provide 12V and 3.3V per the specification and on the ML605 the VADJ supply is connected to 2.5V

> I only have to use 2.5V?    whether 3.3V can be used ?

The 2.5V can be used and the 3.3V can be used, but you cannot connect the ML605 FMC IO that operate on 2.5V to a device that requires 3.3V IO and expect it to work and not cause physical damage.   If you must use a ML605 and you must use the device with 3.3V IO then you must also design in a level translator between the two in order for the design to work correctly.

Note: If the I/O standard that is used is LVDS between the two devices then there will be no issues.

[cxyzkaka]

        The  IO‘voltage Of  the chip，can be  3.3 V  or 2.5 V 。 2.5V can be used as the I/O voltage， but   It's not very common though。

 I decide  to  use 2.5V for the IO of the chip ，so it can  be compatible with FMC 。

        As to the 1.5V voltage for the core of the chip ，I Will use a voltage regulator to step down to 1.5V  from the 3.3V on the FMC。

                 If   the method  is  feasible？

 Because the time difference，the communication is not so convenient。

THANKS

[mcgett]

>  If the method  is  feasible？

Yes, this should be fine.

[cxyzkaka]

HI

 I am come back to ask  a question . Thanks in advance.

 I Will use  the single-ended user defined signals on LPC. 

  1  Should I  connect  PRSNT_M2C_L  to  GND Of  the  pcb?

  2  How  to deal with the   pin  of   PG_C2M  on the pcb?

thanks

[mcgett]

>  1  Should I  connect  PRSNT_M2C_L  to  GND Of  the  pcb?

Yes, becuase this is what the VITA 57.1 FMC speficiation requires. Are you an elecard working together?

> 2 How  to deal with the   pin  of   PG_C2M  on the pcb?

Per the VITA 57.1 FMC Specification, this is an indicator from the Carrier Card that the power supplies are within tolerance. You can choose to use it or not use it on your module.