When i am trying to convert the clipped and filled raster of DEM to ASCII most of the cell values turn to 'no data' values i.e -9999 even though there are no 'no data' values in the original DEM. Also my maximum and minimum elevation values also get changed during this process. Actually i need DEM in the TRIGRS software in ascii format.
when you clipped, did you use a perfect rectangle which was axis-aligned?
if not and you used some other shape, then the no data values represent the space between your clipping shape and what is returned (rasters are rectangular by definition)