Method for dual edge clock and buffer tree synthesis
View Patent ↗A method for balancing both edges of a signal of an integrated circuit (IC) design includes defining a virtual cell to have the same geometry as that of a port of the IC design. First and second input pins of the virtual cell are defined for detecting rising and falling edges. The first and second input pin geometries are defined to be the same as that of the corresponding pins of the port. The virtual cell is overlapped with the port so the first and second input pins are connected to the corresponding port network. The first and second input pins are configured as sinks for clock and buffer tree synthesis. An EDA tool identifies the first and second input pins as additional parallel sinks on the port network and balances the rising and falling edges of the signal at the port.
1. A method for balancing rising and falling edges of a signal of an integrated circuit design stored in a memory using an electronic design automation (EDA) tool executing on a processor, wherein the integrated circuit design includes at least one logic path for transmitting the signal to at least one port having a pre-defined geometry, the method comprising:
defining a virtual cell having a geometry that is the same as the pre-defined geometry of the at least one port;
defining first and second input pins of the virtual cell for detecting rising and falling edges of the signal respectively, such that the first and second input pins and corresponding pins of the at least one port have the same pin geometries;
accessing the integrated circuit design stored in the memory and overlapping the virtual cell with the at least one port of the integrated circuit design such that the first and second input pins are connected to a corresponding network of the at least one port; and
configuring the first and second input pins as sinks, whereby the EDA tool executing on the processor identifies the first and second input pins and corresponding pins of the at least one port as parallel sinks, thereby balancing the rising and falling edges of the signal.
2. The method of claim 1 , wherein the signal is at least one of a clock signal and a data signal.
3. The method of claim 1 , wherein the at least one port is one of an input-output (I/O) port and a hard block port.
4. The method of claim 1 , wherein defining the virtual cell comprises analyzing the pre-defined geometry of the at least one port for shape, size, layer and location.
5. The method of claim 4 , wherein the geometry of the virtual cell is defined such that the shape, size, layer and location of the virtual cell and the first and second input pins are the same as the shape, size, layer and location of the at least one port.
6. The method of claim 1 , wherein the virtual cell is defined such that the virtual cell includes no active elements.
7. The method of claim 1 , wherein the virtual cell is defined such that the first and second input pin capacitances are zero.
8. The method of claim 1 , wherein the EDA tool is operated during clock and buffer tree synthesis of the integrated circuit design.
9. The method of claim 8 , wherein the virtual cell covers the port during the clock and buffer tree synthesis of the integrated circuit design.
10. The method of claim 1 , wherein configuring the first and second input pins comprises keeping a network connected to the first and second input pins of the virtual cell the same as the network connected to the corresponding pins of the port.
11. An EDA tool including at least one processor and at least one memory in communication with the processor, wherein the memory is used to store an integrated circuit design, the EDA tool for balancing rising and falling edges of a signal of the integrated circuit design, wherein the integrated circuit design includes at least one logic path for transmitting the signal to a port having a pre-defined geometry, the EDA tool performing steps including:
defining a virtual cell having a same geometry as the pre-defined geometry of the port;
defining first and second input pins of the virtual cell for detecting rising and falling edges of the signal respectively, wherein the first and second input pins and corresponding pins of the port have the same pin geometries;
accessing the integrated circuit design stored in the memory and overlapping the virtual cell with the port such that the first and second input pins are connected to a corresponding network of the port; and
configuring the first and second input pins as sinks, whereby the EDA tool executing on the processor identifies the first and second input pins and corresponding pins of the port as parallel sinks, thereby balancing the rising and falling edges of the signal.
12. The EDA tool of claim 11 , wherein the steps are performed during clock and buffer tree synthesis of the integrated circuit design.
13. The EDA tool of claim 12 , wherein the port is one of an input-output (I/O) port and a hard block port.
14. The EDA tool of claim 12 , further including the step of analyzing the pre-defined geometry of the port for shape, size, layer, and location.
15. The EDA tool of claim 14 , wherein the geometry of the virtual cell is defined such that the shape, size, layer and location of the virtual cell and the first and second input pins are the same as the shape, size, layer and location of the port.
16. The EDA tool of claim 12 , wherein the virtual cell is defined such that the virtual cell includes no active elements.
17. The EDA tool of claim 12 , wherein the virtual cell is defined such that the first and second input pin capacitances are zero.
18. The EDA tool of claim 12 , wherein the virtual cell covers the port.
19. The EDA tool of claim 12 , further comprising keeping the network connected to the first and second input pins of the virtual cell the same as the network connected to the corresponding pins of the port.