LPC with 4 UARTs

Started by donhamilton2002 March 21, 2009
I am looking for a small LPC device (64 or 48 pins) that has 3 or 4 UARTs.

Look over at NXPs web site, I have found the LPC2468 with 4 UARTs but its in a 208 pin package.

I am looking at collecting three serial data streams, parsing the data I need, then sending the new packet down the line for logging.

Any suggestions ?

don

An Engineer's Guide to the LPC2100 Series

On Sat, 21 Mar 2009 18:27:51 -0000, you wrote:

>I am looking for a small LPC device (64 or 48 pins) that has 3 or 4 UARTs.
>
>Look over at NXPs web site, I have found the LPC2468 with 4 UARTs but its in a 208 pin package.
>
>I am looking at collecting three serial data streams, parsing the data I need, then sending the new packet down the line for logging.
>
>Any suggestions ?
>
>don
>

Soft UARTS - unless data rates are approaching mbits, should be no problem doing several UARTS in
software - use FIQs to guarantee timing if there are a lot of other ints in the system.
--- In l..., "donhamilton2002" wrote:
>
> I am looking for a small LPC device (64 or 48 pins) that has 3 or 4 UARTs.
>
> Look over at NXPs web site, I have found the LPC2468 with 4 UARTs but its in a 208 pin package.
>
> I am looking at collecting three serial data streams, parsing the data I need, then sending the new packet down the line for logging.
>
> Any suggestions ?
>
> don
>

I think NXP makes a series of interface (bridge) chips that do things like serial <-> SPI or I2C.

See http://dkc1.digikey.com/us/en/tod/NXP/Bridge_Solutions/Bridges.swf

Richard

Need to be LPC ?

I would suggest Luminary parts (CortexM3)... LM3S1607, for example, is
64 pins and have 3 uarts...

Regards,
Sergio.
On Sat, Mar 21, 2009 at 3:27 PM, donhamilton2002
wrote:
> I am looking for a small LPC device (64 or 48 pins) that has 3 or 4 UARTs.
>
> Look over at NXPs web site, I have found the LPC2468 with 4 UARTs but its in
> a 208 pin package.
>
> I am looking at collecting three serial data streams, parsing the data I
> need, then sending the new packet down the line for logging.
>
> Any suggestions ?
>
> don
--- In l..., Sergio Sider wrote:
>
> Need to be LPC ?
>
> I would suggest Luminary parts (CortexM3)... LM3S1607, for example, is
> 64 pins and have 3 uarts...

Thanks, I look into this one.

As far as bit-bashing serial ports,

I thought of this and have done it before on lessor processors at lower baud rates. I able to get one stream working at 19,200.

The three streams are 38,400 baud each.

I'll have to think about this real hard before committing brain cells to it.

don

You bet they do:
SC16IS752/SC16IS762

I've used these dual UART parts and they are way cool. They can handle
hardware and software handshaking and have significant buffers built in.
You can get them SPI or I2C as well.

DLC

rtstofer wrote:
> --- In l..., "donhamilton2002" wrote:
>> I am looking for a small LPC device (64 or 48 pins) that has 3 or 4 UARTs.
>>
>> Look over at NXPs web site, I have found the LPC2468 with 4 UARTs but its in a 208 pin package.
>>
>> I am looking at collecting three serial data streams, parsing the data I need, then sending the new packet down the line for logging.
>>
>> Any suggestions ?
>>
>> don
>> I think NXP makes a series of interface (bridge) chips that do things like serial <-> SPI or I2C.
>
> See http://dkc1.digikey.com/us/en/tod/NXP/Bridge_Solutions/Bridges.swf
>
> Richard
>
The STM32F103xxx devices have 5 UARTs. They maybe little faster than what
you need (72MHz), but STM32F101xxx devices (36MHz) have up to 3 UARTs only.

You can get nice overview hier:
http://www.st.com/mcu/inchtml-pages-stm32.html

I'm quite happy with those. There is good docu and free firmware library
(good for reference).

Regards,
Jan
----- Original Message -----
From: "donhamilton2002"
To:
Sent: Sunday, March 22, 2009 1:51 AM
Subject: [lpc2000] Re: LPC with 4 UARTs
--- In l..., Sergio Sider wrote:
>
> Need to be LPC ?
>
> I would suggest Luminary parts (CortexM3)... LM3S1607, for example, is
> 64 pins and have 3 uarts...

Thanks, I look into this one.

As far as bit-bashing serial ports,

I thought of this and have done it before on lessor processors at lower baud
rates. I able to get one stream working at 19,200.

The three streams are 38,400 baud each.

I'll have to think about this real hard before committing brain cells to it.

don

On Sun, 22 Mar 2009 00:51:44 -0000, you wrote:

>--- In l..., Sergio Sider wrote:
>>
>> Need to be LPC ?
>>
>> I would suggest Luminary parts (CortexM3)... LM3S1607, for example, is
>> 64 pins and have 3 uarts...
>
>Thanks, I look into this one.
>
>As far as bit-bashing serial ports,
>
>I thought of this and have done it before on lessor processors at lower baud rates. I able to get one stream working at 19,200.
>
>The three streams are 38,400 baud each.

Shouldn't be a problem - timer interrupt at baud*3 = 8.6uS =~500 cycles at 60MHz
Read the whole port at the start of the FIQ routine to minimise sample jitter, then process each bit
in turn with a simple state machine.
All the state for 3 UARTS should easily fit in the FIQ banked registers, so the only memory access
needed would be the buffer write, and using the banked regs also means no significant context-save
time.
I'd guess something like 10-15 instructions per UART channel, even with pretty straightforward
coding ( maybe even in C if the compiler knows how to use the FIQ regs properly!) so the CPU loading
would be pretty minimal - a few %.
For maximum speed you might want to put the FIQ code in RAM.
--- In l..., "donhamilton2002" wrote:
>
> I am looking for a small LPC device (64 or 48 pins) that has 3 or 4 UARTs.
>
> Look over at NXPs web site, I have found the LPC2468 with 4 UARTs but its in a 208 pin package.
>
> I am looking at collecting three serial data streams, parsing the data I need, then sending the new packet down the line for logging.
>
> Any suggestions ?
>
> don
>

LPC23xx also has four UARTs and is available in LQFP100 and LQFP144 Package.