1ch uart w/ narrow parallell interface...?

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Are there any uarts around with a "narrow" parallell interface which can
be utilized from a uC w/o a full-blown address/data bus system? I am
aware of the possibility of using SPI-type uarts - but for various
reasons those are not an alternative this time.

I was thinking about the possibility of using 8-9-10 general IO lines on
a uC and I guess I should use an interrupt line as well.

Small footprint, low pin count, smd (of course), low price?

Ideas, anyone?

--
Torbjørn Heltne

Re: 1ch uart w/ narrow parallell interface...?
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It would be useful if you could add a little more detail to your
requirements such as speed.

Depending on how busy your uC is, you could bit-bang the serial port if the
data rate is not too high.  We have done this on projects where space and
cost were at an absolute premium.

It was not clear why you can't use SPI, but if what you mean is you can't
use SPI for the serial port, you might use a separate small micro that has
both SPI and serial.  You talk to the SPI port from your micro and it talks
to the serial port.

Scott



Re: 1ch uart w/ narrow parallell interface...?
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Hi,

How about a micro with built-in serial. PIC16F628, or PIC16F870 both
have uarts.

--
Luhan Monat: luhanis(at)yahoo(dot)com
http://members.cox.net/berniekm
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Re: 1ch uart w/ narrow parallell interface...?
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Speed requirements are <= 38400, amount of data max 150cps in each
direction. I have read some on a few bit-banged serial port
implementations. Common for all of them were that they were half duplex
only. I need full duplex. I guess it is absolutely possible to achieve
that but I think I prefer a hardware solutiuon anyway.
I'm not too sure why I don't want to use the SPI-interface for asynch
SCI communication. You're more than welcome to give me reasons to do it
that way.


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I'm already aiming for a micro with built in serial, the ATmega16. I
need a second serial port.

--
Torbjørn Heltne

Re: 1ch uart w/ narrow parallell interface...?
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Why not go for the ATmega162. It has two serial ports.

Meindert



Re: 1ch uart w/ narrow parallell interface...?

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I can do without the TWI but need a couple of A/D channels.

--
Torbjørn Heltne

Re: 1ch uart w/ narrow parallell interface...?
Hi,

the LPC915 has UART, 4 ADC channels and 2K FLASH.  It is much cheaper
than ATmega of the PIC16 proposed and does not even need an oscillator
(internal RC)

Schwob

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Re: 1ch uart w/ narrow parallell interface...?
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Mmmm... I am alway very sceptic about internal oscillators in combination
with UARTS. What do others think? Good/bad experiences?

Meindert



Re: 1ch uart w/ narrow parallell interface...?
On Sat, 27 Nov 2004 07:53:06 +0100, the renowned "Meindert Sprang"

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<shrug> It's rated at +/-2.5% over temperature (and +/-1% at room
temperature). That sounds good enough to me if the divider granularity
doesn't add too much additional error, especially if you're
communicating with something that uses a crystal.


Best regards,
Spehro Pefhany
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"it's the network..."                          "The Journey is the reward"
snipped-for-privacy@interlog.com             Info for manufacturers: http://www.trexon.com
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Re: 1ch uart w/ narrow parallell interface...?


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For a single UART, the ATmega48 is a better choice.

--
Best Regards,
Ulf Samuelsson   ulf@a-t-m-e-l.com
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Re: 1ch uart w/ narrow parallell interface...?
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The smallest Std UART with a narrow parallel BUS is the 2691 from
Philips. Comes in 24 DIP and SO packages.


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You may find that a small uC with SPI+UART, is cheaper/smaller than a
small UART. Philips have tiny LPC91x series uC devices as small as 14
pins, with UART and SPI ports, so you can add as many Duplex UARTS as
you want....

-jg


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