R
rider
Guest
Hi!
I have to redesign a TTL based design of discere components into an
FPGA. I have selected spartan 2 xc2s150. I have a few queries
regarding the board design.
1) I want my Inputs to be 5V tolerant..which input standard should i
use...LVTTL or PCI_5V ? How to select any of these standards as both
require VCCO=3.3V and No Vref or VTT...?
2)If any of my xc2s150 ouput pin is an open collector, can i pull it
up externally by 5V through a resistor?
3)I am intending to use a Level shifter IC(3.3V to 5V) at some FPGA
outputs..is it OK to do so?
4)I dont have a global set/reset in the design, can it create problems
at startup?
5)What should i do of un-used pins of FPGA...can i keep them
unconnected?
Thanks for everyone's support.
I have to redesign a TTL based design of discere components into an
FPGA. I have selected spartan 2 xc2s150. I have a few queries
regarding the board design.
1) I want my Inputs to be 5V tolerant..which input standard should i
use...LVTTL or PCI_5V ? How to select any of these standards as both
require VCCO=3.3V and No Vref or VTT...?
2)If any of my xc2s150 ouput pin is an open collector, can i pull it
up externally by 5V through a resistor?
3)I am intending to use a Level shifter IC(3.3V to 5V) at some FPGA
outputs..is it OK to do so?
4)I dont have a global set/reset in the design, can it create problems
at startup?
5)What should i do of un-used pins of FPGA...can i keep them
unconnected?
Thanks for everyone's support.