28 Dec
2006
28 Dec
'06
10:44 a.m.
9000 VAX wrote:
If my memory is correct, 16 byte buffer exists on
16450 and 16550 UART
chips. The 8250 has only one byte buffer.
Are either of the 16450/16550 a drop-in replacement for an 8250, or are
they not pin/command compatible? From what _I_ rememebr, the 16450 is a direct
replacement for the 8250,
and has only th 1-byte buffer. The 16550 has the 16 byte
FIFO and is pin
compatible with the 8250 (and after reset the FIFO is disabled so it
works like a 8250 too).
Replacing 8250s with 16550s was a common upgrade on PC serial cards some
years ago. It used to be claimed the upgrade was only possbile if the
8250 was socketed, needless to say that didn't bother me. The serial card
in this PC has been upgraded that way...
-tony