Characters sent "back to back" or in isochronous mode, still are received in accordance with standard asynchronous technique, which means nothing happens once the stop bit is generated, and things remain so until the start bit (opposite in sense to the stop bit) is detected. Then, the sampling begins one-half bit-time later and continues sampling in phase with that event at the bit rate for those 9 bits. If there's error (bit-frame slip) within the stop bit, it matters not, nor does it really quite get to the threshold, since it's got a half-bit of slack anyway. The sampling typically is timed from a timebase of 16x the sample rate, which means that the beginning of the start bit is always detected at the next (16x) clock. That has to be taken into consideration if one is operating very close to the margin. Both ends do have to be working with the same data format, of course.

RE