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LVS error concerning multiplicity of transistors + IBM cms9flp

jimito13
jimito13 over 15 years ago

Hello everyone,

I came up with the following LVS error concerning all transistors with multiplicity factor m (NOT with just fingers and no multiplicity factor in contrary) in my design.LVS debug environment details give the following description :

FET1comp has mismatched parameter(s):"w" layout: 1.5e-05 schematic: 7.5e-06

Let me be more specific.For the above description,in my design i have a transistor with Wtotal=15um and multiplicity factor m=2 (thus 2 fets in parallel with 7.5um width each),well,assura can make the correct computation for the layout and it shows the actual Wtotal but it cannot estimate the correct value for the Wtotal for the side of the schematic (it seems considering m=1 always independent from the value i have set in the fet properties).Is there any way to get rid of this error (with some switch under Modify avParameters menu for example) or i should make any change to the compare rules file to the respective funtion?I show you the properties of the nfet :

Width Single Finger : 7.5u
Width All Fingers :7.5u
Fingers :1
Multiplicity :2

Thus,Wtotal=15u as i mentioned earlier.

The following lines contain the part of the compare.vldb file with the respective section for the FET1comp function :

procedure( FET1comp(m1, m2)
let((paraminfolist )
paraminfolist='(
("l" "abs_comp" "if(BentGate<0.5 then hgp else hgp7)")
("w" "abs_comp" "if(BentGate<0.5 then hgp else hgp7)")
)
unless(getValCase(m1 "m") m1->m=1)
unless(getValCase(m2 "m") m2->m=1)
unless(getValCase(m1 "idg") m1->idg=0)
unless(getValCase(m2 "idg") m2->idg=0)
if( (m1->idg && abs_comp(m1->idg 0 0.5)) then
m1->w = getValCase(m1 "w") * getValCase(m1 "m") )
if( (m2->idg && abs_comp(m2->idg 0 0.5)) then
m2->w = getValCase(m2 "w") * getValCase(m2 "m") )
unless(getValCase(m1 "bentgate") m1->bentgate=0)
unless(getValCase(m2 "bentgate") m2->bentgate=0)
BentGate = m1->bentgate + m2->bentgate
genericcomp("FET1comp" m1 m2 paraminfolist)
)
) 

I must say that i use IBM cms9flp pdk finally if somebody didn't notice that on the post subject.Also Cadence IC 6.1.3 under opensuse 11.1 operating system 64-bit.

Can somebody give me a helpful hint how to solve this problem?Changing all transistor to bus will be a painful procedure for me and i want to avoid it if possible.

Thanks in advance for any helpful answer and if more clues are needed ask me to post them here.

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  • jimito13
    jimito13 over 15 years ago

     Hello Quek,

     At first thanks for your interest to my problem.I run the command in ciw but the cell.cdf output file is empty(!),so there is no reason to upload.What can we see from this file if it had something in it?

     The file with .vlr extension is IBM confidential and i can't post it or upload it anywhere...Guide me with a similar file that apparently you have as well and i will give you the feedback for the thing that we must know from that file.

     Output from the 2 commands in terminal :

     IC6.1.3.500.13

    3.2_USR2_HF11

    Regards

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  • jimito13
    jimito13 over 15 years ago

     Hello Quek,

     At first thanks for your interest to my problem.I run the command in ciw but the cell.cdf output file is empty(!),so there is no reason to upload.What can we see from this file if it had something in it?

     The file with .vlr extension is IBM confidential and i can't post it or upload it anywhere...Guide me with a similar file that apparently you have as well and i will give you the feedback for the thing that we must know from that file.

     Output from the 2 commands in terminal :

     IC6.1.3.500.13

    3.2_USR2_HF11

    Regards

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    • Vote Up 0 Vote Down
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