i A PHYSICAL IMPLEMENTATION WITH CUSTOM LOW POWER ...

In addition to power rings, the power bus resistance can be minimized by the addition of
vertical power stripes connecting the power rings. The “addStripe” command can be used to add
power stripes [9]. The final part of the initialization routine uses the “sroute” command to route
the standard cell power and ground rails [9].
ALU Floor plan/ Power plan routine
The “ibm_setalumod.tcl” is used to floorplan the ALU modules. ALU modules are placed
at pre-determined locations using the “setObjFPlanBox” command [9]. The script automatically
calculates the X and Y co-ordinates of the ALU module. The parameter CUR_X and CUR_Y
describe the X and Y co-ordinate of the lower left corner of the bounding box of the ALU
module. The parameters NEXT_X and NEXT_Y describe the X and Y co-ordinate of the top
right corner of the bounding box of the ALU module. The parameters CUR_X, CUR_Y,
NEXT_X and NEXT_Y are internally generated based on the ALU module’s width and height
and need not be given as an input to the user.
ALU Module Pin assignment
Pins can be assigned to a partition using the “preassignPin” command by specifying the
X and Y co-ordinates of the pin location along with the layer on which the pin has to be assigned
[9]. The “ibm_pinassign_alu_module.tcl” is used to assign pins to the ALU module. The
important consideration during pin placement is that each process has a pre-defined horizontal
and vertical pin grid given by the technology vendor. Hence, all pins placed in the horizontal
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