io limited v/s core limited design

[mvvijay78]

is design io limited?

Hi,
I would like to know how to identify if a design is IO limited or core limited.Once decided what is the methodology to be followed to hand;e each one of them?
Regards
Vicky

 

[suituse]

core limited or io limited

The easiest way to find design is core limited or pad limited is if you use the fattest iopad for the all the io ports and still find there are gaps in the io row, this design is core-limited. Otherwise it is pad limited.
One of the difference between them is the choose between in-line pads or staggered pads. In the pad limited design the bonding pads are usually placed staggered to reduce the total die size, and in the core limited design shorter and wider pads should be used and placed inline.
And io filler cells should be used whenver there are gaps between iopads.

 

[giggs11]

core limited io

If the number of IO ports of a design is small, the the padframe would be typically small in area or perimeter. Now, if the design's perimeter was larger than the padframe's perimeter, this would be termed core limited. Core limited IO pads are "fatter" or wider than IO limited pads.

If the number of IO ports of a design is large, then the padframe's perimeter would be large and should the design's perimeter be smaller, then this would be a case of IO limited.

Hope it helps.

 

[surigoodguy]

Re: core limited io

If the number of IO ports of a design is small, the the padframe would be typically small in area or perimeter. Now, if the design's perimeter was larger than the padframe's perimeter, this would be termed core limited. Core limited IO pads are "fatter" or wider than IO limited pads.

If the number of IO ports of a design is large, then the padframe's perimeter would be large and should the design's perimeter be smaller, then this would be a case of IO limited.

Hope it helps.

if the number of IO ports of a design is" large" & "small" ,, how do we say small in the sense any min number of pads? am using 32 io pads in my design ,,, it means its io limited?? is there any other way to find it