For the Philips Signetics Dual UART, P/N SCC 68692 has anyone seen the
following problems with newer parts.  We don't seem to have problems with
older parts, 1994 date code.  We have the problems with newer parts 2000
and 2001 parts.  We don't know where the date change actually occurred.
The problems don't happen 100% of the time on the new parts.  Temperature
seems to affect it.  The problem occurrs more often at higher
temperatures.

The problems are:
1.  The baud rate is wrong by a factor of 16.  If you select 19.2K baud
for example, the part tries for 307K baud.

2.  The part drops bits on the output data and requires 3 tries on any
RS232 input to get the correct character.  For instance, if you are
pressing a series of 1's on the keyboard, then press 2, it will take 3
presses of 2 before the 2 is actually outputed on the UART.  The problem
seems to be in changing bits on the output word from low to high.  If a
bit is high and is intended to be high, it will stay high.  If a bit is
low and is intended to stay low, it will stay low.  If a bit is high and
needs to go low, it will go low on the first key press.  If a bit is low
and needs to go high, it will take 3 key presses to go high.



Dennis Petrosky
Circuit Card Manufacturing Engineer
607-763-4745