UART In the new design

How about the UART that comes on most 186 parts these days?

The 8251 is obsolete, unless someone's taken it up again -- probably because everything under the sun has a built-in UART these days. The last time I had to do a search the only thing available was a Philips part and their peripherals are _twisted_.

The 8251 is obsolete. There are several variations on the 16550 UARTs (singles, duals, quads, variying amount of FIFO memory). These are available from TI, Philips and several other manufacturers.

If you could make the 8251 work, then you will be able to use a 16550 type with a little bit of extra work for programming the registers.

But you can still get 8251s. For example, Jameco

Rob Young

What other 'support chips', are you likely to need?. There are a lot of 'all in one' chips available, that give you some programmable I/O, timers, UART etc., in a single chip. If you need more than just the UART, it might be worth considering one of these.

Best Wishes

Naimesh schrieb:

As Tim pointed out, finding something dedicated might be difficult. You could also glue a 89C2051 with a small CPLD to your 186. Might also be cheaper.

Regards Markus

"Naimesh" wrote

Along with the suggestions of high-integration '186 uPs and the 16550 you might want to try the 2651 family.

I would contact the mfg. before design-in to make sure the part is not scheduled to go down the tubes in the near future.

Parts with high military usage often stay around for a long while.

I use the MAX3100 UART for this sort of add-on. Needs SPI bus to operate, but thats pretty standard on most controllers. May not be available on a 'bare' 186 processor.

"Naimesh" schreef in bericht news: snipped-for-privacy@z14g2000cwz.googlegroups.com...

In the old days of the first IBM PCs the 8250 was choosen. It was said almost obsolete but it was used in AT's as well. It was a horrible thing as there were lots of small differences between manufacturers and series and a lot of them were also buggy. New, compatible UARTS were developed and the

petrus bitbyter

I can believe they are stable, but I heard the classic PC COM port doesn't do hardware handshaking correctly. I can't recall the details but I'm told it was a known problem but nobody would fix it for fear of incompatibility problems, and that there are software kludges to tackle it.

RS232 ports are disappearing from the desktop. Has the OP considered a USB chip? I've just used a chip from FTDI and it makes interfacing even easier than a UART chip. No pesky baud rates for example.

K.