Special engineering change order cells
View Patent ↗A method for correcting a plurality of violations in a circuit design and new cells used in the method are disclosed. The method generally includes the steps of (A) implementing a first engineering change order in the circuit design to correct a first of the violations, (B) implementing a second engineering change order with a special cell to correct a second of the violations, the special cell having a plurality of interfaces available for a signal path associated with the second violation, each of the interfaces having a characteristic appropriate to correct the second violation, each of the characteristics having a different performance and (C) routing the signal path to one of the interfaces to fix the second violation.
1. An apparatus comprising:
a first circuit configured to generate a first output signal at a first output by performing a first operation on at least three first input signals received through at least three first inputs; and
at least three second circuits each configured to generate a different second output signal at a different second output by performing a second operation on a different second input signal, wherein (i) each of said second input signals is received at a different second input through a boundary of said apparatus, (ii) each of said second outputs is connected to a different one of said first inputs, (iii) said second operations implement an engineering change order suitable to correct a violation in a circuit design, (iv) each of said second operations has a different value of a performance and (v) all except one of said second input signals are fixed to a respective logic value according to said first operation to correct said violation.
2. The apparatus according to claim 1 , wherein said different values of said performance comprise different propagation delays.
3. The apparatus according to claim 1 , further comprising a third circuit configured to generate a third output signal at a third output through said boundary of said apparatus by performing a third operation on a plurality of third input signals received through a plurality of third inputs, wherein a predetermined one of said third inputs is connected to said first output.
4. The apparatus according to claim 1 , wherein (i) a middle of said performances is calculated to correct said violation, (ii) a higher of said performances is offset from said middle performance by a first amount and (iii) a lower of said performances is offset from said middle performance by a second amount opposite said first amount.
5. The apparatus according to claim 1 , further comprising a plurality of third circuits each configured to generate a different third output signal at a different third output by performing a third operation on a different third input signal received through a different third input, wherein (i) all of said third inputs are connected to said first output, (ii) said third operations implement another engineering change order suitable to correct another violation in said circuit design, (iii) each of said third operations has a different value of another performance and (iv) all except one of said third output signals are left unconnected to correct said other violation.
6. The apparatus according to claim 1 , wherein said first output comprises an output through said boundary of said apparatus.
7. A method for correcting a violation in a circuit design, comprising the steps of:
(A) generating a first output signal at a first output of a first circuit by performing a first operation on at least three first input signals received through at least three first inputs; and
(B) generating at least three different second output signals in at least three second outputs of a second circuit by performing a second operation on each of at least three second input signals, wherein (i) each of said second input signals is received at a different second input through a boundary, (ii) each of said second outputs is connected to a different one of said first inputs, (iii) said second operations implement an engineering change order suitable to correct said violation in said circuit design, (iv) each of said second operations has a different value of a performance, (v) all except one of said second input signals are fixed to a respective logic value according to said first operation to correct said violation and (vi) the steps are preformed by processor executable instructions contained within a non-transitory computer readable medium.
8. The method according to claim 7 , further comprising the step of:
generating a third output signal at a third output through said boundary by performing a third operation on a plurality of third input signals received through a plurality of third inputs, wherein a predetermined one of said third inputs is connected to said first output.
9. The method according to claim 7 , further comprising the step of:
generating at least three different third output signals in at least three third outputs by performing a third operation on each of at least three third input signals received through at least three third inputs, wherein (i) all of said third inputs are connected to said first output, (ii) said third operations implement another engineering change order suitable to correct another violation in said circuit design, (iii) each of said third operations has a different value of another performance and (iv) all except one of said third output signals are left unconnected to correct said other violation.
10. An apparatus comprising:
a first circuit configured to generate a first output signal at a first output by performing a first operation on at least one first input signal received through at least one first input; and
at least three second circuits each configured to generate a different second output signal at a different second output by performing a second operation on a different second input signal, wherein (i) each of said second output signals is presented at a different second output through a boundary of said apparatus, (ii) all of said second inputs are connected to said first output, (iii) said second operations implement an engineering change order suitable to correct a violation in a circuit design, (iv) each of said second operations has a different value of a performance and (v) all except one of said second output signals are left unconnected to correct said violation.
11. The apparatus according to claim 10 , wherein said different values of said performance comprise different propagation delays.
12. The apparatus according to claim 10 , wherein said different values of said performance comprise different ramp times.
13. The apparatus according to claim 10 , wherein (i) a middle of said performances is calculated to correct said violation, (ii) a higher of said performances is offset from said middle performance by a first amount and (iii) a lower of said performances is offset from said middle performance by a second amount opposite said first amount.
14. The apparatus according to claim 10 , further comprising a plurality of third circuits each configured to generate a different third output signal at a different third output by performing a third operation on a different third input signal received at a different third input, wherein (i) one said third outputs is coupled to said first input, (ii) each of said third operations implements another engineering change order suitable to correct another violation in said circuit design, (iii) each of said third operations has a different value of another performance and (iv) all except one of said third input signals are fixed to a respective logic value according to said first operation to correct said other violation.
15. The apparatus according to claim 10 , wherein said first input comprises an input through said boundary of said apparatus.
16. A method for correcting a violation in a circuit design, comprising the steps of:
(A) generating a first output signal at a first output of a first circuit by performing a first operation on at least one first input signal received through at least one first input; and
(B) generating at least three different second output signals in at least three second outputs of a second circuit by performing a second operation on each of at least three second input signals, wherein (i) each of said second output signals is presented at a different second output through a boundary, (ii) all of said second inputs are connected to said first output, (iii) said second operations implement an engineering change order suitable to correct said violation in said circuit design, (iv) each of said second operations has a different value of a performance and (v) all except one of said second output signals are left unconnected to correct said violation and (vi) the steps are preformed by processor executable instructions contained within a non-transitory computer readable medium.
17. The method according to claim 16 , wherein (i) a middle of said performances is calculated to correct said violation, (ii) a higher of said performances is offset from said middle performance by a first amount and (iii) a lower of said performances is offset from said middle performance by a second amount opposite said first amount.
18. The method according to claim 16 , further comprising the step of:
generating at least three different third output signals in at least three third outputs by performing a third operation on each of at least three third input signals received at least three third inputs, wherein (i) one said third outputs is coupled to said first input, (ii) said third operations implement another engineering change order suitable to correct another violation in said circuit design, (iii) each of said third operations has a different value of another performance and (iv) all except one of said third input signals are fixed to a respective logic value according to said first operation to correct said other violation.