请教conformal中unreachable point的排除问题

screw

我在使用conformal LEC做rtl与netlist做验证的时候，工具报告出很多unreachable point，其中相当一部分并不是没有fanout的点，请问要如何分析tool给出的这段报告来判断是否这个unreachable point是否可以忽略？我从fanin/fanout的信息中没法判断出为什么tool说这是个unreachable point.

请大家给些建议~~~谢谢！
/
/ Command: report gate uvc/rdc8051/rst_osc_ctl/pHFWake_reg -golden -unreach ================================================================================ Pin-name ID (Golden) Type Tie Gate-name ================================================================================ 1765 DFF /uvc/rdc8051/rst_osc_ctl/pHFWake_reg ------ Fanins ------------------------------------------------------------------ 1: 'S' 6792 ZERO /uvc/rdc8051/rst_osc_ctl/N$4 2: 'R' 6792 ZERO /uvc/rdc8051/rst_osc_ctl/N$4 3: 'CK' 19219 AND /uvc/clk_gen/DNT_ANDCPUCLK/U$1 4: 'D' 34584 AND /uvc/rdc8051/rst_osc_ctl/U$27 ------ Fanouts ----------------------------------------------------------------- 1: 34575 INV /uvc/rdc8051/rst_osc_ctl/U$57 2: 34573 AND /uvc/rdc8051/rst_osc_ctl/U$53 3: 34579 AND /uvc/rdc8051/rst_osc_ctl/U$30 ================================================================================ // Report unreachable information for '1765 DFF /uvc/rdc8051/rst_osc_ctl/pHFWake_reg' // 1: Reached '1788 DFF /uvc/rdc8051/rst_osc_ctl/pFWake_reg' // 2: Reached '1765 DFF /uvc/rdc8051/rst_osc_ctl/pHFWake_reg' // 3: Stopped at '1765 DFF /uvc/rdc8051/rst_osc_ctl/pHFWake_reg' due to visited // This gate is unreachable from any primary output // Command: report gate uvc/rdc8051/rst_osc_ctl/pHFWake_reg/_i0/U$1 -revised -unreach ================================================================================ Pin-name ID (Revised) Type Tie Gate-name (Library: FFDHD1X) ================================================================================ 1760 DFF /uvc/rdc8051/rst_osc_ctl/pHFWake_reg/_i0/U$1 ------ Fanins ------------------------------------------------------------------ 1: 'S' 11570 INV (L0) /uvc/rdc8051/rst_osc_ctl/pHFWake_reg/U$0 2: 'R' 11571 AND (L0) /uvc/rdc8051/rst_osc_ctl/pHFWake_reg/U$3 3: 'CK' 34194 AND /uvc/clk_gen/DNT_ANDCPUCLK/U$1 4: 'D' 57327 OR /uvc/rdc8051/rst_osc_ctl/pHFWake_reg/U$4 ------ Fanouts ----------------------------------------------------------------- 1: 62962 AND /uvc/rdc8051/rst_osc_ctl/pFWake_reg/U$6 2: 57317 INV /uvc/rdc8051/rst_osc_ctl/pHFWake_reg/_i1 ================================================================================ // Report unreachable information for '1760 DFF /uvc/rdc8051/rst_osc_ctl/pHFWake_reg/_i0/U$1' // 1: Reached '1785 DFF /uvc/rdc8051/rst_osc_ctl/pFWake_reg/_i0/U$1' // 2: Reached '1760 DFF /uvc/rdc8051/rst_osc_ctl/pHFWake_reg/_i0/U$1' // 3: Stopped at '1760 DFF /uvc/rdc8051/rst_osc_ctl/pHFWake_reg/_i0/U$1' due to visited // This gate is unreachable from any primary output 我從報告出的fanin/fanout，以及report的信息，判斷不出爲什麽tool會認為這個FF是unreachable的。想請教您該如何去分析tool給出的這組信息？

qingwatiaowu

我的report里也有很多个unreachable points，仔细查看了一下
是很多定义的reg没用到的bits，感觉没关系

别人设计的东西多出来的没用到的bits

demetrio

太复杂的东东
咱也不懂

yale9301

unreachable表示对output没有贡献，也就是这些points与output port没有数据路径。
如果一个DFF为unreachable ，可能导致其fanin相关的DFF也为unreachable。

zyf___wh

coformal
thanks
thanks!!!

nelsonafn

目前，许多感谢。

lling65

需要debug

kk2009

一般来说unreachable的都是对输出没有贡献的，可以不管的。。。

chinaqu

学到了，谢谢

amapola

please check your pin constraint first.