i solved... the problem was from CONFIG . MCLRE must be off and measured pulse is in 10us.

#CONFIG
__config _INTRC_OSC_NOCLKOUT & _WDT_OFF & _MCLRE_OFF & _CP_OFF
#ENDCONFIG

ansel = 0
wpu = 0
cmcon0 = 7
signal var word

main:

pulsin gpio.3,1,signal
if signal > 160 then high gpio.0


goto main
end