|  | # Power nets | 
|  | set ::power_nets $::env(_VDD_NET_NAME) | 
|  | set ::ground_nets $::env(_GND_NET_NAME) | 
|  |  | 
|  | pdngen::specify_grid stdcell { | 
|  | name grid | 
|  | core_ring { | 
|  | met5 {width $::env(_WIDTH) spacing $::env(_SPACING) core_offset $::env(_H_OFFSET)} | 
|  | met4 {width $::env(_WIDTH) spacing $::env(_SPACING) core_offset $::env(_V_OFFSET)} | 
|  | } | 
|  | rails { | 
|  | } | 
|  | straps { | 
|  | met4 {width $::env(_WIDTH) pitch $::env(_V_PITCH) offset $::env(_V_PDN_OFFSET)} | 
|  | met5 {width $::env(_WIDTH) pitch $::env(_H_PITCH) offset $::env(_H_PDN_OFFSET)} | 
|  | } | 
|  | connect {{met4 met5}} | 
|  | } | 
|  |  | 
|  | pdngen::specify_grid macro { | 
|  | instance "obs_core_obs" | 
|  | power_pins $::env(_VDD_NET_NAME) | 
|  | ground_pins $::env(_GND_NET_NAME) | 
|  | blockages "li1 met1 met2 met3 met4 met5" | 
|  | straps { | 
|  | } | 
|  | connect {} | 
|  | } | 
|  |  | 
|  |  | 
|  | pdngen::specify_grid macro { | 
|  | power_pins $::env(_VDD_NET_NAME) | 
|  | ground_pins $::env(_GND_NET_NAME) | 
|  | blockages "" | 
|  | straps { | 
|  | } | 
|  | connect {} | 
|  | } | 
|  |  | 
|  | set ::halo 0 | 
|  |  | 
|  | # POWER or GROUND #Std. cell rails starting with power or ground rails at the bottom of the core area | 
|  | set ::rails_start_with "POWER" ; | 
|  |  | 
|  | # POWER or GROUND #Upper metal stripes starting with power or ground rails at the left/bottom of the core area | 
|  | set ::stripes_start_with "POWER" ; | 
|  |  |