[gmx-users] continuing the terminated simulation

[delara aghaie]

Dear Gromacs users
Hello,
I use gromacs version 4.5.5. I have started with Lysozime in water simulation. (Justin tutorials)
The md part of simulation was terminated. Now I want to continue the simulation from the interruption point. Is this command line correct?
mdrun -deffnm md_0_1      -s    md_0_1.tpr       -cpi      md_0_1.tpr.cpt???

I am not sure whether to use only -cpi md_0_1.tpr.cpt with mdrun command or both .tpr and .cpt files???

another question is that whether continuing the simulation should be done via file md_0_1.tpr.cpt  or md_0_1.tpr_prev.cpt ? and what in the difference between them?

Thanks in advance
Regards
D.M