gopstein@soleil.UUCP (Rich Gopstein) (10/28/89)
I have an application where I need to take 5 bits-per-character serial data at very slow baud (approx 50 baud), and send it serially to a PC via the RS-232 port. I can accomplish this with two back-to-back UARTS running at different clock speeds and different bits-per-character. I don't plan to include a microprocessor in this device, only two UARTS, two clocks, and some drivers. I have looked around at a couple of UARTS, but the ones I looked at (8250, 2651?) were designed to interface to a computer bus. I need UARTS that can be strapped to run with the desired bits-per-character, stop-bits, etc. (i.e. I want a UART whose configuration is set via its external pins, not via an internal register that must be set each time the power is applied to the device). Thanks in advance. -- Rich Gopstein ..!rutgers!soleil!gopstein
peg@psuecl.bitnet (10/29/89)
In article <826@soleil.UUCP>, gopstein@soleil.UUCP (Rich Gopstein) writes: > > I have looked around at a couple of UARTS, but the ones I looked at > (8250, 2651?) were designed to interface to a computer bus. I need > UARTS that can be strapped to run with the desired bits-per-character, > stop-bits, etc. (i.e. I want a UART whose configuration is set via > its external pins, not via an internal register that must be set each Hey! I suggest you look for one of several UART's. I don't have much data on any of them (well, I do somewhere, but can't find it!!), but I think they might do the job. 1) 6402 or 6403 2) AY-3-1015 or AY-5-1013 (General Instruments, et al) This is off the top of my head, though, and my memory is kinda fuzzy. These are rather old UART's--I believe they were used in many of the early terminals/TTY's that had no processors. They are still available, though; I know Jameco has them. If I can find the data sheets (I might have trashed them) I'll let you know. Oh, wait!! The CMOS cookbook (Don Lancaster-Sams Books) has a circuit using the 6402. It is pin-strapped, but needs an external clock. I think one of the AY's has an internal oscillator. I'll keep looking! Anyone else know more? Paul
mwilson@crash.cts.com (Marc Wilson) (10/29/89)
In article <826@soleil.UUCP> gopstein@soleil.UUCP (Rich Gopstein) writes: > >I have an application where I need to take 5 bits-per-character serial >data at very slow baud (approx 50 baud), and send it serially to >a PC via the RS-232 port. > >I have looked around at a couple of UARTS, but the ones I looked at >(8250, 2651?) were designed to interface to a computer bus. I need >UARTS that can be strapped to run with the desired bits-per-character, >stop-bits, etc. (i.e. I want a UART whose configuration is set via >its external pins, not via an internal register that must be set each >time the power is applied to the device). > The UART for you is the TMS-1602. This is the original, generic UART. Strppable for any combination of word length, parity, stop bits, etc. BTW... why are you doing this this way? Why not just set up the PC serial chip ( an 8250 is sooo easy! ) with the parameters you need? You can write an interrupt routine to run in the background so's you're not watching the port all the time. >Thanks in advance. > >-- >Rich Gopstein > >..!rutgers!soleil!gopstein -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Marc Wilson ARPA: ...!crash!mwilson@nosc.mil ...!crash!pnet01!pro-sol!mwilson@nosc.mil UUCP: [ cbosgd | hp-sdd!hplabs | sdcsvax | nosc ]!crash!mwilson INET: mwilson@crash.CTS.COM ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~