. ignore interrupt (stop interrupt check loop) if
interrupt bit not set; limit loop too
. mask off other bits when testing bits in the status register
. this fixes rs232 output that would otherwise never get re-triggered
as too many bits were set in the status byte to match the
possibilities.
Change-Id: I311c93377fa8fb477ee9a756455fdeda780e6ba1
93d9caa2d6