Lpc2000

I just recieved 3 pieces of the LPC2214FBD144 (144 pin part) from 
philips as samples.  I was working on a rather complicated atmel 
AT91RM9200 design with all the bells and whistles, but since these 
parts arrived so quickly, I am considering putting that design on 
hold for a bit and getting something actually working by using the 
LPC2214.  Just to get something going, I am considering stripping my 
design down to the following:

LPC2214FBD144
2 channel 16 bit DAC on SPI #1
8 channel 8 bit DAC on SPI #2
16 bit compact flash connector interface on the external memory 
controller
RS485 level converter on UART0
RS232 level converter on UART1
output buffers for DACS (+/-10 volts on the 16 bit DACS, 0-5 volts on 
the 8 bit, unless I find a 8 channel 8 bit dac with 0-5 volt buffers 
built in)
Simple linear voltage regulators

To keep things as simple as possible, I will supply regulated 5V and 
+/- 12V externally, and use onboard 1.8v,3.3v,10v,-10v linear 
regulators.  I will bring out the rest of the IO to .1 inch headers, 
and also perhaps the address/data bus to .1 inch headers for 
experiments.

Do you think this simple design is remotely possible on a 2 layer 
board?  I would love to keep it at two layers for cost reasons.

Thanks,

Rick

At 17:39 2004-02-20, you wrote:
>I just recieved 3 pieces of the LPC2214FBD144 (144 pin part) from
>philips as samples.  I was working on a rather complicated atmel
>AT91RM9200 design with all the bells and whistles, but since these
>parts arrived so quickly, I am considering putting that design on
>hold for a bit and getting something actually working by using the
>LPC2214.  Just to get something going, I am considering stripping my
>design down to the following:
>
>LPC2214FBD144
>2 channel 16 bit DAC on SPI #1
>8 channel 8 bit DAC on SPI #2

  If this is for your laser controller, I would recommend parallel DACs. 
You will have a bottleneck with SPI, and since you've got an external 
memory interface, use that.

>16 bit compact flash connector interface on the external memory
>controller

  For true-ide? What kinds of cards do you plan to support? You don't need 
the full CF bus for true-ide.

>RS485 level converter on UART0

  I guess this is for DMX512. Watch out for the break detection of the 
USART controller.

>RS232 level converter on UART1

  MIDI? Or just plain RS232?

>output buffers for DACS (+/-10 volts on the 16 bit DACS, 0-5 volts on
>the 8 bit, unless I find a 8 channel 8 bit dac with 0-5 volt buffers
>built in)

  What kind of inputs has your laser? 8-bit DACs are typically 
differential. The motor 16-bit DACs are usually both differential and bipolar.

  Have you considered an ILDA-compliant interface?

>Do you think this simple design is remotely possible on a 2 layer
>board?  I would love to keep it at two layers for cost reasons.

  *Too* risky. To get the most of the 16-bit DACs, a ground plane is a 
must. It saves a lot of headaches and layout time. Of course, always 
separate your analog circuits from your digital signals.

  Regards.

----- Original Message ----- 

From: "skykotech" <rick@...>
To: <lpc2000@yahoogroups.com>
Sent: Friday, February 20, 2004 8:39 PM
Subject: [lpc2000] lpc2214 samples


> I just recieved 3 pieces of the LPC2214FBD144 (144 pin part) from
> philips as samples.  I was working on a rather complicated atmel
> AT91RM9200 design with all the bells and whistles, but since these
> parts arrived so quickly, I am considering putting that design on
> hold for a bit and getting something actually working by using the
> LPC2214.  Just to get something going, I am considering stripping my
> design down to the following:
>
> LPC2214FBD144
> 2 channel 16 bit DAC on SPI #1
> 8 channel 8 bit DAC on SPI #2
> 16 bit compact flash connector interface on the external memory
> controller
> RS485 level converter on UART0
> RS232 level converter on UART1
> output buffers for DACS (+/-10 volts on the 16 bit DACS, 0-5 volts on
> the 8 bit, unless I find a 8 channel 8 bit dac with 0-5 volt buffers
> built in)
> Simple linear voltage regulators
>
> To keep things as simple as possible, I will supply regulated 5V and
> +/- 12V externally, and use onboard 1.8v,3.3v,10v,-10v linear
> regulators.  I will bring out the rest of the IO to .1 inch headers,
> and also perhaps the address/data bus to .1 inch headers for
> experiments.
>
> Do you think this simple design is remotely possible on a 2 layer
> board?  I would love to keep it at two layers for cost reasons.


It should be possible, if you are reasonably skilled at doing PCB layouts. I
wouldn't use an autorouter, unless you have a really good (and expensive)
one like Specctra or Electra. You might need to go down to 6/6 mil design
rules, to keep the board a reasonable size, and use small vias. Use 0805 Rs
and Cs and put them on the back of the board. PCB-Pool can make double-sided
boards down to 6/6, with 0.3 mm holes for the vias, as standard. Not many
other low-cost suppliers can manage those parameters. Getting neat routing
to the connectors is likely to be the biggest problem, you will have a lot
of tracks to get in.

Four-layers would be *much* easier but about twice as expensive.

Leon
--
Leon Heller, G1HSM
Email: aqzf13@...
My low-cost Philips LPC210x ARM development system:
http://www.geocities.com/leon_heller/lpc2104.html

--- In lpc2000@yahoogroups.com, "skykotech" <rick@s...> wrote:
> I just recieved 3 pieces of the LPC2214FBD144 (144 pin part) from 
> philips as samples.  I was working on a rather complicated atmel 
> AT91RM9200 design with all the bells and whistles, but since these 
> parts arrived so quickly, I am considering putting that design on 
> hold for a bit and getting something actually working by using the 
> LPC2214.  Just to get something going, I am considering stripping
my 
> design down to the following:

Are they making the 2214?  What did you have to do to get a sample? 
Do you have any idea when it will be in production?  If this will be
in production anytime in the next three months, I will seriously
consider them vs. the OKI parts I am planning to use. 

 
> LPC2214FBD144
> 2 channel 16 bit DAC on SPI #1
> 8 channel 8 bit DAC on SPI #2
> 16 bit compact flash connector interface on the external memory 
> controller
> RS485 level converter on UART0
> RS232 level converter on UART1
> output buffers for DACS (+/-10 volts on the 16 bit DACS, 0-5 volts
on 
> the 8 bit, unless I find a 8 channel 8 bit dac with 0-5 volt
buffers 
> built in)
> Simple linear voltage regulators
> 
> To keep things as simple as possible, I will supply regulated 5V
and 
> +/- 12V externally, and use onboard 1.8v,3.3v,10v,-10v linear 
> regulators.  I will bring out the rest of the IO to .1 inch
headers, 
> and also perhaps the address/data bus to .1 inch headers for 
> experiments.
> 
> Do you think this simple design is remotely possible on a 2 layer 
> board?  I would love to keep it at two layers for cost reasons.

Yes, I don't think the part will be hard to route on a two layer board
if you don't mind it using a lot of space for vias.  The OKI eval
board I am using only has two layers for signals and most of them run
very directly from chip to chip because they left tons of space
between them.  

Just use fat power traces and a lot of decoupling caps (one for each
power pin) right next to the Vdd pin with the shortest possible path
to a GND pin on the chip.

--- In lpc2000@yahoogroups.com, Pablo Bleyer Kocik <pbk@e...> wrote:
> At 17:39 2004-02-20, you wrote:
> >I just recieved 3 pieces of the LPC2214FBD144 (144 pin part) from
> >philips as samples.  I was working on a rather complicated atmel
> >AT91RM9200 design with all the bells and whistles, but since these
> >parts arrived so quickly, I am considering putting that design on
> >hold for a bit and getting something actually working by using the
> >LPC2214.  Just to get something going, I am considering stripping 
my
> >design down to the following:
> >
> >LPC2214FBD144
> >2 channel 16 bit DAC on SPI #1
> >8 channel 8 bit DAC on SPI #2
> 
>   If this is for your laser controller, I would recommend parallel 
DACs. 
> You will have a bottleneck with SPI, and since you've got an 
external 
> memory interface, use that.

Yes, this is for a first run of the laser controller...sort of a get 
my feet wet thing.  Why should I have a bottleneck with SPI?  The DAC 
chip I want to use (TLV5630 if I just go all 12 bit, or TLV5632 if I 
go cheap and 8 bit) has a maximum SPI serial clock rate of 30mhz.  
The LPC2214 can operate its SPI at 1/8 of the pclk, or 7.5mhz for a 
60mhz clock from the PLL.  It takes 128 clock cycles to update all 
eight dacs which is 17.07uS.  Oh, ouch...the SPI data register is 
only 8 bits...thats a lot of cpu time just dinking with the 
registers....good point.  Too bad they didn't put a dma controller in 
the package.



> 
> >16 bit compact flash connector interface on the external memory
> >controller
> 
>   For true-ide? What kinds of cards do you plan to support? You 
don't need 
> the full CF bus for true-ide.
> 
> >RS485 level converter on UART0
> 
>   I guess this is for DMX512. Watch out for the break detection of 
the 
> USART controller.
> 
> >RS232 level converter on UART1
> 
>   MIDI? Or just plain RS232?
> 
> >output buffers for DACS (+/-10 volts on the 16 bit DACS, 0-5 volts 
on
> >the 8 bit, unless I find a 8 channel 8 bit dac with 0-5 volt 
buffers
> >built in)
> 
>   What kind of inputs has your laser? 8-bit DACs are typically 
> differential. The motor 16-bit DACs are usually both differential 
and bipolar.
> 
>   Have you considered an ILDA-compliant interface?
> 
> >Do you think this simple design is remotely possible on a 2 layer
> >board?  I would love to keep it at two layers for cost reasons.
> 
>   *Too* risky. To get the most of the 16-bit DACs, a ground plane 
is a 
> must. It saves a lot of headaches and layout time. Of course, 
always 

> separate your analog circuits from your digital signals.
> 
>   Regards.

> Are they making the 2214?  What did you have to do to get a sample? 
> Do you have any idea when it will be in production?  If this will be
> in production anytime in the next three months, I will seriously
> consider them vs. the OKI parts I am planning to use. 
> 

Well, I sent an email a few days ago stating that I am considering 
several ARM chips for my design and I would consider using the 
LPC2214 if they were going to be available soon, and what was the 
liklihood of getting samples for a prototyp. They sent me back an 
email saying samples were on the way.

Seems like pretty nice customer service.  :-)

Rick