Timing noise, glitches and the braking index of PSR B0540-69

We report a pulse-time history of PSR B0540-69 based on the analysis of an extended data set including ASCA, BeppoSAX and RXTE observations spanning a time interval of about 8 years. This interval includes also the epoch of the glitch episode reported by Zhang et al. ([CITE]). Our analysis shows the presence of relevant timing noise and does not give clear evidence of the glitch occurrence. We performed an accurate evaluation of the main timing parameters, ν , $\dot{\nu}$ and $\ddot{\nu}$ and derived a mean braking index of $n=2.125\pm0.001$ quite different from the lower value found by Zhang et al. ([CITE]), but in rather good agreement with several other values reported in the literature.