ICC的LVS出现了VSS的open，所有出现先VSS的地方全部出错了
在verify_lvs的时候出现了float和一个vssopen，open整个白茫茫的一片，出现VSS的地方都出现了错误，没法具体定位，是哪里设置不合理了吗?ERROR : OUTPUT PortInst fzu8051_top_inst/MCU8051/i_cpu/cyc1/U9 Y doesn't connect to any net.
ERROR : INPUT PortInst fzu8051_top_inst/MCU8051/i_cpu/cyc1/U9 A(429955) in net VSS(462112) is floating.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/xunhuan1/sval_reg[11] Q doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/xunhuan1/sval_reg[9] Q doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/xunhuan1/sval_reg[17] Q doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/round16_end_dout1/dout_in_reg[20] QN doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/round16_end_dout1/dout_in_reg[12] QN doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/round16_end_dout1/dout_in_reg[19] QN doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/shuchuchuli1/dout1_reg[44] QN doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/shuchuchuli1/dout1_reg[43] QN doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/round16_end_dout1/dout_in_reg[8] QN doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/round16_end_dout1/dout_in_reg[9] QN doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/shuchuchuli1/dout1_reg[53] QN doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/round16_end_dout1/dout_in_reg[26] QN doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/round16_end_dout1/dout_in_reg[25] QN doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/shuchuchuli1/dout_final_reg[34] QN doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/shuchuchuli1/dout1_reg[40] QN doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/shuchuchuli1/dout1_reg[41] QN doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/round16_end_dout1/dout_in_reg[14] QN doesn't connect to any net.
ERROR : OUTPUT PortInst fzu8051_top_inst/DES/shuchuchuli1/dout1_reg[50] QN doesn't connect to any net.
整个图中出现VSS的地方，几乎都出错了！
期待大神回复。是否是因为没有via什么的?
有没有tie 和 drive_pg_connection.
drive_pg_connection
output open没关系
先verify_pg_nets 确认PG有没有问题，check_mv_design 去看power 连接，都没问题了再搞PV
有连接，我又特意去连了一下。 怎看看是不是via的问题呢，其他地方via都可以自动用上的说
所有output的float都没事吗?
电源地有链接的，不知道是不是因为之前修DRC的时候，修改了下网表，但是没改VSS的说。
http://bbs.eetop.cn/thread-441780-1-1.html
恩恩verify_pg_nets 的rail都给修了，我再去试试
看来下感觉都没什么问题的说，警告之前也出现过，做PV是什么意思呢?
icc_shell> check_mv_design-power_nets--------------------------------------------------------------------------------
Power/Ground Pin Connection Checks
--------------------------------------------------------------------------------
Power/Ground Connection Summary:
P/G net nameP/G pin count
--------------------------------------------------------------------
Other power nets:12404
Unconnected power pins:0
Other ground nets:12404
Unconnected ground pins:0
--------------------------------------------------------------------
Warning: Power connection/checking is skipped for 24800 power pins because the required power pin information cannot be found in logical libraries. (MV-510)
--------------------------------------------------------------------------------
Supply Operating Voltage Checks
--------------------------------------------------------------------------------
No Errors/Warnings Found.
Please review report above for warnings and errors.
1
icc_shell> verify_pg_nets
Cell design_top.err existed already. Delete it ...
Checking [VDD]:
There are no floating shapes
All the pins are connected.
No errors are found.
Checking [VSS]:
There are no floating shapes
All the pins are connected.
No errors are found.
Checked 2 nets, 0 have Errors
input不能floating但是output是可以的，只要确实是floating的，那就没问题
和另个帖子的问题应该没关系。如果不放心，可以从头来一遍试试
恩恩，感觉那边也没改到VSS，不过之前一次没出现open，我再去试一下看看
看来下IO的文档里面写着要加隔离PBREAK，里面推荐的pad的摆放方式像下图那样，是不是所有的电源pad最好这样摆放呢，因为感觉电源pad一般会放到四周去。PVDD是1.8VPDVDD是3.3V
PBREAK is used to break power and ground rings and to isolate substrate. They have back-to-back diodes between different ground signals
问题解决了，input的错误route_eco可以解决。
应该是我在布std_rail得时候，没有设置不要经过宏单元，现在设置完了后，就可以了
所以floating就是route_eco解决的?
output的还有，但是input的是route_eco解决的，刚开始open也还是存在的，不过这次ECO也也把它解决了
嗯 这样 有时候我这里也是很多floating
小编你好请问icc中verify_lvs一版是在什么时候检查啊routing后吗 ，floorplan后lvs有问题可以ignore吗
最后做lvs check，前面做没啥意义
感谢大神
我做verify_PG_net 时 :Checking [VDD]:
There are no floating shapes
ERROR: There are 981 floating pins
check_mv_design 是没有错误，怎么回事呢 ?
thanks