Skip to main content

Hold fixing

 Endpoint hold fixing : more number of buffer addition , Less TAT, more predictable or sure shot fix.

DMSA hold fixing : Optimal number of buffer , Common point buffer insertion .

Comments

Post a Comment

Popular posts from this blog

GBA vs PBA

 Graph based path analysis : Tool consider worst input slew for setup and best input slew for hold analysis ( worst delay for setup and best delay for hold ) . Run time is less and pessimistic analysis . Path based analysis : actual input slew is used ,so delay value will be accurate . Longer runtime .
Post a Comment
Read more

Physical cells used in IC design

 Why endcap cells are used in design ? There are high chances to get damaged the gate of standard cells placed at the boundary during the manufacturing of chip. Nwell terminates within endcap cells , so we cannot replace filler with endcap as filler is for nwell continuity , also dummy poly layers present in endcap cells protect from wave proximity effect. Tap cells differ in such a way that nwell continuous and not continuous in endcap cells . To avoid the base layer DRC (Nwell and Implant layer) at the boundary. To make the proper alignment with the other block. The end cap cell or boundary cell is placed at both the ends of each placement row to terminate the row.  It has also been placed at the top and bottom row at the block level to make integration with other blocks End caps are added before std cells placement and are preplaced fixed cells which added immediately after site row creation. Boundary cells have mainly Nwell layer, implant layers, and dummy poly layer and m...
Post a Comment
Read more

MCMM

Multi-mode multi-corner (MMMC) analysis refers to performing STA across  multiple operating modes ,  PVT corners  and  parasitic interconnect corners  (rcworst , cworst etc ) at the same time. MCMM file is To analyse the design over various modes and corners .   VLSI design can be modeled in either functional or test mode etc Each mode at varied process corners. We need to ensure that the design is stable across all corners (PVT corners ). Mode : A mode is defined by a set of clocks, timing constraints, Supply voltage and libraries. Many chip have multiple modes such as functional modes, test mode, sleep mode, etc Corner: A corner is defined as a set of libraries characterized for process, voltage, and temperature variations (cell line) and interconnect corner .Corners are not dependent on functional settings; they are meant to capture variations in the manufacturing process, along with expected variations in the voltage and temperature of the environment i...
Post a Comment
Read more