pranav r. phatak wrote:
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if you are having a problem with i/o simply use delay as mahmood has reccomended.
for initialization few milisec are sufficient.for other commands the delay req.is smaller.check your LCD manual.

I would like to add that if you are using LCD's controlled by the HD44780, its datasheet is available and should probably be viewed as the ultimate authority on how to interface with the device. The datasheet shows two methods of initialization, one with internal reset, the other is initialization by instruction.

This latter method is for cases when the power supply conditions are not suitable to generate the internal reset. The HD44780 datasheet flowchart clearly states that the busy flag cannot be checked until the initialization sequence is (nearly) complete, regardless of the data interface width.

My experience is to not rely on the internal reset means, and to utilize the "initialization by instruction" means. Even if the internal reset can be generated, it does not hurt employ the initialize by instruction code. Plus, then you've got a reusable code module that should work in any situation.