7271 - MACHXO3: Why does the Diamond software still allow the LVCMOS10R33 and LVCMOS10R25 IO types on speed grade -5 of MachXO3LF when the documentation says speed grade -6 devices only support them?
Solution:
The datasheet only shows speed grade -6 support for LVCMOS10R33 and LVCMOS10R25 IO types because it can cover all the frequency range up to the fmax parameter of speed grade -6 devices.
The Diamond software still allows LVCMOS10R33 for speed grade -5 devices because it can still support LVCMOS10R33 and LVCMOS10R25, but with low frequency input only.
Note: It cannot cover all the frequency range up to the fmax parameter of speed grade -5 devices.