关于SRVF中的 3个问题。必看，请高手解答。

soszhangshu

小弟我在看SRVF时  在关于LVS 的时候遇到了 3个语句看不懂 分别是 ：
1  LVS EXPAND SEED PROMOTION (YES/NO)
2 LVS  EXPAND UNBALANCE CELL (YES/NO)
3  LVS INJECT LOGIC                    (YES/NO)
求大侠知道 。小弟我不甚感激

soszhangshu

这3个语句分别是什么意思 。做什么用 。求高手解答。。小弟不甚感激

motofatfat

SRVF 我也不懂
以下是 卡利博  SVRF 的解釋

LVS EXPAND SEED PROMOTIONS
Used only in Calibre nmLVS-H and PERC

Description
Instructs the hierarchical nmLVS circuit comparison module whether or not to expand hcells
that were subject to seed promotion during device recognition. Seed promotion occurs when
hierarchical device recognition is unable to completely process devices within a cell, and
promotes those devices out of the cell and places them at a higher level of hierarchy. When YES
is specified, cells that were subject to seed promotion out of the cell do not serve as hcells in
hierarchical circuit comparison. This statement may appear only once in a rule file.
The nmLVS hierarchical SPICE netlister places *.SEEDPROM statements in all subcircuits
that were subject to seed promotion. This is done regardless of the LVS Expand Seed
Promotions setting.
This statement operates on hcells specified explicitly (for example, in an hcell list) as well as
implicitly (for example, with -automatch). However, LVS Box cells are not expanded by this
statement.
Hcells expanded by this statement are indicated with warnings in the circuit comparison
transcript.

soszhangshu

呵呵 。这个英文我也看了 。可是就是没有看懂呀 。。。继续等高人 ，求解

allen_tang

1. seed promotion是mentor的叫法，我覺得大概是一个hierarchy内的device。
3.LVS INJECT LOGIC应该是run hierarchy的LVS时，calibre会把类似结构的mos视为hierarchy由此来提高验证速度，参考calibre提取layout的.sp的netlist，写法跟电路差别很大，但实际的电路中可能并不是完全一致而导致lvs错误，应该都是option为no.

另外求1、2的解释.

allen_tang

mentor官方论坛上apps工程师的解释：

Hi Kumark,


I'd like to contribute a few ideas to the discussion you started. I'd be very interested in other ideas from more people too.


From my perspective "seeds" are an important part of "devices", and "promotion" is another way of saying "moved to a higher level". So with those two ideas together, "seed promotion" can be thought of as another way to describe a case where devices ended up at higher levels than expected.


A device in Calibre LVS is comprised of the seed shape (device body) and pins. For a mosfet the seed shape is typically the intersection of poly and diffusion. The pins are typically the source and drain (typically defined as diffusion NOT poly) and the gate pin (typically poly), and a bulk pin (typically a well, or substrate).


One of the most common causes of seed promotion is the calculation of certain properties that relate to the device, but aren't the same for every placement of that device. These properties might be relative to the seed shape or the pins associated with the seed shape. AS and AD are examples of properties that have caused problems of this nature for years. If a source pin on a device, in a cell, has a certain AS property value that is different in one placement than another, then that device can't really be described accurately in both locations by using just one property value.


W and L have never been a problem because the W and L of a device in a cell is typically the same in every placement of that cell.


AS and AD are not always the same because the calculations of these values can change depending upon the relationship of cell placements with each other. for instance, a cell could be placed once, with no cells nearby, and the AS/AD would be calculated with a certain value. Then the same cell might be placed somewhere else as a pair of mirrored cells where the source pins of the mosfets are shared. The AS/AD properties would be different in this case. The subckt representing the placed cell would no longer be able to reflect accurate values for AS and AD because the values would be different for different placements. the affected transistors would typically be "promoted" up until the devices were present in some higher subckt (flattened in other words) so that each could now be represented with different AS/AD values reflecting the different placements of the same cell.


There is much more that we could discuss in the area of seed promotion but before I go further it might be good to stop and check to see if this is the type of information you were interested in.


Best regards,

-chris

jimmylin

非常的感謝分享

billcxx

Thanks I interesting in seed promtions for RCX hier,,some one can push back to the hcell ,but some can't ,I don't know why ? who can explain?

icfbicfb

都为缺省值就行了，不是特别重要的选项，