mukesh,

"E" is the data strobe. The timing diagrams i have used in the past come from SEIKO and indicate entering the write (or read) cycle with "E" low. The setup time from the assertion of wr=0 and RS=0/1 prior to setting "E" high is given as 140 ns(tAS). "E" is to be set high for 450 ns (PWEH) and then asserted low (where the actual data latches). Data is indicated as being stable and valid for 195 ns(tDSW) prior to setting "E" low.

This info comes from an old SEIKO Document;
"Liquid Crystal Display Character Modules Application Notes" SI-9034/10-89/5M. This doc include timing, command description, trouble shooting and example code. If this doc is anywhere on the WEB get it. I believe it would answer every question this board has seen to date on character LCD's.

regards,
p