meet skew via constraint

setOptMode -ignorePathGroupsForHold {in2reg reg2reg in2out} -holdTargetSlack 0 -setupTargetSlack 0 -fixHoldAllowSetupTnsDegrade false

setOptMode -holdFixingCells {BUFFER_NAME}

setDelayCalMode -engine xxx -SIAware true -signoff true

set_analysis_view -setup funcPostC_PVT_setup  -hold funcPostC_PVT_setup

update_constraint_mode -name funcPostC -sdc_files “constraint_file_path”

optDesign -postRoute -outDir ./rpts/fix_skew_setup

update_constraint_mode -name funcPostC -sdc_files “constraint_file_path”

setOptMode -fixHoldAllowSetupTnsDegrade true

optDesign -postRoute -hold -outDir ./rpts/fix_skew_hold

constraint file

set DQS_TSEL_SEL {tsel_dqs_1_opad tsel_dqs_2_opad tsel_dqs_3_opad}

set dqs_delay_max 0.65
set dqs_delay_min 0.65
set range 0.015

foreach k $DQS_TSEL_SEL {
set_load -pin_load -max  0.025  $k
set_load -pin_load -min  0.025  $k
set_max_delay [expr $dqs_delay_max + $range] \
-from STA_check_begReg_N/CPN \
-to ${k}
set_max_delay [expr $dqs_delay_max + $range] \
-from STA_check_begReg/CP \
-to ${k}
set_min_delay [expr $dqs_delay_min – $range] \
-from STA_check_begReg_N/CPN \
-to ${k}
set_min_delay [expr $dqs_delay_min – $range] \
-from STA_check_begReg/CP  \
-to ${k}
}

STA skew result in worst corner

MAX_TSEL_SKEW 0.125 actual_skew_dqs_tsel_rise 0.028
MAX_TSEL_SKEW 0.125 actual_skew_dqs_tsel_fall 0.038
MAX_TSEL_SKEW 0.125 actual_skew_dqs_tsel 0.046
MAX_TSEL_DELAY 1.2 actual_delay_dqs_tsel 0.655