Ocean script: Extract clock period jitter

here is the simple Cadence ocean script to extract clock periods. The results can be used to calculate the period jitter and cycle-to-cycle jitter in the excel spread sheet (post processing).






;_____________________________________________

simulator( 'spectre )
;Output file name
p = outfile( "_jitter.txt" "w")

openResults( "/PATH_TO_DESIGN/spectre/schematic" )
selectResult( 'tran )



;-----------------------------------
; Setting
;----------------------------------

vcc = 1.8
threshold = 0.9

t0_edge = 1

% set a large number in the for_loop counter so it can extract the entire sim results
for(i 1 200000

t1_edge = t0_edge + i
t2_edge = t1_edge + 1


;----------------
; measurement
;----------------

per_buf3 = ( cross(v("/buf3") threshold t2_edge "rising") - cross(v("buf3") threshold t1_edge "rising"))
per_buf3b = ( cross(v("/buf3b") threshold t2_edge "rising") - cross(v("buf3b") threshold t1_edge "rising"))



;----------------
; Print out
;----------------

fprintf( p "%-14e" per_buf3 )
fprintf( p "%-14e" per_buf3b )
fprintf( p "\n" )
)

close(p)