既然都這樣說了
有空的看看吧...
This paper presents a greedy refinement technique for IR-drop
reduction. The authors applied a fast IR drop estimation method
of an existing work to locate the row with maximum IR-drop, and
to reduce it's IR-drop by moving the cells in that row to other
rows with less IR-drop.
1.
a).
The resistive model for standard cells in this paper is equivalent to
a VCCS source with
I = Ps/V + k*V (derived from Equation (4) and (5)
considering that P=V*I), where Ps is standard power consumption,
I is the value of the current source,
V is the voltage difference from power pin and ground pin and
k is a parameter related to clock rate and etc.. In some situations,
for example, if the static power consumption larger than dynamic power
consumption, the current will increase while V decreases, the model
contradicts with the behavior of any existed standard cell.
b). The resistive model SHOULD not be directed grounded. For constant
current model the voltage cross a cell and the output current is
independent to each other.
The current source can be grounded without any problem. But it is not
the case in the resistive or other any VCCS model. Those resistors
should be connected to both the ground network and the power network.
Due to the above reasons, the reviewer doubts the accuracy of this model.
The experimental results should have be verified with commercial tools,
such as powerrail, voltagestorm, or HSPICE.
2. The contribution of this paper is Theorem 1. But it is trivial for
electronic circuits. Removing a standard cell which consumes current
will no doubt reduce IR-drop. If removing a standard cell out of a
row will increase IR-drop, the model of the power/ground network is
definitely wrong.
--
如果早上沒有從窗口照進來的陽光，那麼
早晨就一點意義都沒有了。
如果醒來的時候腦海中的第一個念頭不是你，那麼
我寧願繼續沈睡。
--
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※ 編輯: moonshade 來自: 203.203.83.87 (05/29 02:05)
※ 編輯: moonshade 來自: 203.203.83.87 (05/29 02:05)
※ 編輯: moonshade 來自: 203.203.83.87 (05/29 02:05)
※ 編輯: moonshade 來自: 203.203.83.87 (05/29 02:06)
※ 編輯: moonshade 來自: 203.203.83.87 (05/29 02:06)
※ 編輯: moonshade 來自: 203.203.83.87 (05/29 02:07)