LPC2138 GPIO
Started by ●April 27, 2005
Hi,
Does the LPC2138 P0.10 pin have special electrical specs.? When
configured as GPIO, it goes to only 2V when in logic '1' output, no
load. Tried with 2 different chips already.
Could someone give me a hint?
Thanks :)
Di
Reply by ●April 27, 20052005-04-27
I saw the same thing when I was evaluating the 2138. I was told by the
Phillips FAE to use external pull-ups when the I/O pin is configured
as an output. The internal weak pull-up works fine when the I/O is
configured as an input. --- In lpc2000@lpc2..., "dimed77" <dimed77@y...> wrote:
>
> Hi,
>
> Does the LPC2138 P0.10 pin have special electrical specs.? When
> configured as GPIO, it goes to only 2V when in logic '1' output, no
> load. Tried with 2 different chips already.
> Could someone give me a hint?
>
> Thanks :)
>
> Di
Reply by ●April 27, 20052005-04-27
Ouch!
-Bill
On Wed, 27 Apr 2005 13:34:13 -0000, tah2k wrote:
I saw the same thing when I was evaluating the 2138. I was told by the
Phillips FAE to use external pull-ups when the I/O pin is configured
as an output. The internal weak pull-up works fine when the I/O is
configured as an input. --- In lpc2000@lpc2..., "dimed77" <dimed77@y...> wrote:
>
> Hi,
>
> Does the LPC2138 P0.10 pin have special electrical specs.? When
> configured as GPIO, it goes to only 2V when in logic '1' output, no
> load. Tried with 2 different chips already.
> Could someone give me a hint?
>
> Thanks :)
>
> Di
-Bill
On Wed, 27 Apr 2005 13:34:13 -0000, tah2k wrote:
I saw the same thing when I was evaluating the 2138. I was told by the
Phillips FAE to use external pull-ups when the I/O pin is configured
as an output. The internal weak pull-up works fine when the I/O is
configured as an input. --- In lpc2000@lpc2..., "dimed77" <dimed77@y...> wrote:
>
> Hi,
>
> Does the LPC2138 P0.10 pin have special electrical specs.? When
> configured as GPIO, it goes to only 2V when in logic '1' output, no
> load. Tried with 2 different chips already.
> Could someone give me a hint?
>
> Thanks :)
>
> Di
Reply by ●April 27, 20052005-04-27
Do any of the other I/O lines that are configured as an Output exhibit
the same problem or is it just that one (P0.10).
I asked Philips in the beggining about the internal pull-ups for the
2138 and the response was as follows:
"
1) pull-up resistors are in the 10s of K - We should have an exact
value after analyzing process data.
2) Port 0 does have pull ups but note that i2c pins do not.
"
regards,
Charles
--- In lpc2000@lpc2..., "Bill Knight" <BillK@t...> wrote:
> Ouch!
>
> -Bill >
> On Wed, 27 Apr 2005 13:34:13 -0000, tah2k wrote:
>
> I saw the same thing when I was evaluating the 2138. I was told by the
> Phillips FAE to use external pull-ups when the I/O pin is configured
> as an output. The internal weak pull-up works fine when the I/O is
> configured as an input. > --- In lpc2000@lpc2..., "dimed77" <dimed77@y...> wrote:
> >
> > Hi,
> >
> > Does the LPC2138 P0.10 pin have special electrical specs.? When
> > configured as GPIO, it goes to only 2V when in logic '1' output, no
> > load. Tried with 2 different chips already.
> > Could someone give me a hint?
> >
> > Thanks :)
> >
> > Di
Reply by ●April 27, 20052005-04-27
The i2c pins must have external 10k pull ups added to work as GPIO
correctly...this is not documented clearly at all!!
Good Luck!!
correctly...this is not documented clearly at all!!
Good Luck!!
Reply by ●April 27, 20052005-04-27
According to page 76-77 of the user manual P0.2, P0.3, P0.11, P0.14 are
open drain outputs for i2c use. These need pullups when used as output
because they will only pull low. FYI, All P1 pins have internal (~50k?)
pullups if used as inputs. P0 pins do not. Jeff.
-----Original Message-----
From: lpc2000@lpc2... [mailto:lpc2000@lpc2...]
On Behalf Of mfrazier@mfra...
Sent: Wednesday, April 27, 2005 7:38 AM
To: lpc2000@lpc2...
Subject: Re: [lpc2000] LPC2138 GPIO The i2c pins must have external 10k pull ups added to work as
GPIO
correctly...this is not documented clearly at all!!
Good Luck!! ________________________________
> .
Reply by ●April 27, 20052005-04-27
Thanks guys, but now I realized there might be a problem with the power
supply. I'll check all the I/O pins again, after this issue is solved.
Di
charlesgrenz <charles.grenz@char...> wrote:
Do any of the other I/O lines that are configured as an Output exhibit
the same problem or is it just that one (P0.10).
I asked Philips in the beggining about the internal pull-ups for the
2138 and the response was as follows:
"
1) pull-up resistors are in the 10s of K - We should have an exact
value after analyzing process data.
2) Port 0 does have pull ups but note that i2c pins do not.
"
regards,
Charles
--- In lpc2000@lpc2..., "Bill Knight" <BillK@t...> wrote:
> Ouch!
>
> -Bill >
> On Wed, 27 Apr 2005 13:34:13 -0000, tah2k wrote:
>
> I saw the same thing when I was evaluating the 2138. I was told by the
> Phillips FAE to use external pull-ups when the I/O pin is configured
> as an output. The internal weak pull-up works fine when the I/O is
> configured as an input. > --- In lpc2000@lpc2..., "dimed77" <dimed77@y...> wrote:
> >
> > Hi,
> >
> > Does the LPC2138 P0.10 pin have special electrical specs.? When
> > configured as GPIO, it goes to only 2V when in logic '1' output, no
> > load. Tried with 2 different chips already.
> > Could someone give me a hint?
> >
> > Thanks :)
> >
> > Di
---------------------------------
Yahoo! Groups Links
To __________________________________________________
Di
charlesgrenz <charles.grenz@char...> wrote:
Do any of the other I/O lines that are configured as an Output exhibit
the same problem or is it just that one (P0.10).
I asked Philips in the beggining about the internal pull-ups for the
2138 and the response was as follows:
"
1) pull-up resistors are in the 10s of K - We should have an exact
value after analyzing process data.
2) Port 0 does have pull ups but note that i2c pins do not.
"
regards,
Charles
--- In lpc2000@lpc2..., "Bill Knight" <BillK@t...> wrote:
> Ouch!
>
> -Bill >
> On Wed, 27 Apr 2005 13:34:13 -0000, tah2k wrote:
>
> I saw the same thing when I was evaluating the 2138. I was told by the
> Phillips FAE to use external pull-ups when the I/O pin is configured
> as an output. The internal weak pull-up works fine when the I/O is
> configured as an input. > --- In lpc2000@lpc2..., "dimed77" <dimed77@y...> wrote:
> >
> > Hi,
> >
> > Does the LPC2138 P0.10 pin have special electrical specs.? When
> > configured as GPIO, it goes to only 2V when in logic '1' output, no
> > load. Tried with 2 different chips already.
> > Could someone give me a hint?
> >
> > Thanks :)
> >
> > Di
---------------------------------
Yahoo! Groups Links
To __________________________________________________
Reply by ●April 27, 20052005-04-27
On Wednesday 27 April 2005 10:37 am, mfrazier@mfra... wrote:
> The i2c pins must have external 10k pull ups added to work as GPIO
> correctly...this is not documented clearly at all!!
There is also the Linear Tech. LTC1694 - SMBus/I²C Accelerator
that may be used in place of the pull ups.
Improves SMBus Rise Time Transition
Ensures Data Integrity with Multiple Devices
on the SMBus
Improves Low State Noise Margin
Auto Detect Low Power Standby Mode
Wide Supply Voltage Range: 2.7V to 6V
Low Profile (1mm) SOT-23 (ThinSOT™)
http://www.linear.com/pc/productDetail.do?navId=H0,C1,C1007,C1070,P1710
> The i2c pins must have external 10k pull ups added to work as GPIO
> correctly...this is not documented clearly at all!!
There is also the Linear Tech. LTC1694 - SMBus/I²C Accelerator
that may be used in place of the pull ups.
Improves SMBus Rise Time Transition
Ensures Data Integrity with Multiple Devices
on the SMBus
Improves Low State Noise Margin
Auto Detect Low Power Standby Mode
Wide Supply Voltage Range: 2.7V to 6V
Low Profile (1mm) SOT-23 (ThinSOT™)
http://www.linear.com/pc/productDetail.do?navId=H0,C1,C1007,C1070,P1710
Reply by ●May 2, 20052005-05-02
I have just tested the P0.10 on my system and it is 3.3V!! I am
using LPC2138
Did they fix the P0.10 issue on new chips?
Thanks,
Gus
--- In lpc2000@lpc2..., Diana Medeiros <dimed77@y...> wrote:
> Thanks guys, but now I realized there might be a problem with the
power supply. I'll check all the I/O pins again, after this issue is
solved.
> Di
> charlesgrenz <charles.grenz@s...> wrote:
>
> Do any of the other I/O lines that are configured as an Output
exhibit
> the same problem or is it just that one (P0.10).
>
> I asked Philips in the beggining about the internal pull-ups for
the
> 2138 and the response was as follows:
>
> "
> 1) pull-up resistors are in the 10s of K - We should have an exact
> value after analyzing process data.
> 2) Port 0 does have pull ups but note that i2c pins do not.
> "
>
> regards,
> Charles
>
> --- In lpc2000@lpc2..., "Bill Knight" <BillK@t...> wrote:
> > Ouch!
> >
> > -Bill
> >
> >
> >
> > On Wed, 27 Apr 2005 13:34:13 -0000, tah2k wrote:
> >
> > I saw the same thing when I was evaluating the 2138. I was told
by the
> > Phillips FAE to use external pull-ups when the I/O pin is
configured
> > as an output. The internal weak pull-up works fine when the I/O
is
> > configured as an input.
> >
> >
> > --- In lpc2000@lpc2..., "dimed77" <dimed77@y...> wrote:
> > >
> > > Hi,
> > >
> > > Does the LPC2138 P0.10 pin have special electrical specs.?
When
> > > configured as GPIO, it goes to only 2V when in logic '1'
output, no
> > > load. Tried with 2 different chips already.
> > > Could someone give me a hint?
> > >
> > > Thanks :)
> > >
> > > Di > ---------------------------------
> Yahoo! Groups Links
>
> To > __________________________________________________
>
using LPC2138
Did they fix the P0.10 issue on new chips?
Thanks,
Gus
--- In lpc2000@lpc2..., Diana Medeiros <dimed77@y...> wrote:
> Thanks guys, but now I realized there might be a problem with the
power supply. I'll check all the I/O pins again, after this issue is
solved.
> Di
> charlesgrenz <charles.grenz@s...> wrote:
>
> Do any of the other I/O lines that are configured as an Output
exhibit
> the same problem or is it just that one (P0.10).
>
> I asked Philips in the beggining about the internal pull-ups for
the
> 2138 and the response was as follows:
>
> "
> 1) pull-up resistors are in the 10s of K - We should have an exact
> value after analyzing process data.
> 2) Port 0 does have pull ups but note that i2c pins do not.
> "
>
> regards,
> Charles
>
> --- In lpc2000@lpc2..., "Bill Knight" <BillK@t...> wrote:
> > Ouch!
> >
> > -Bill
> >
> >
> >
> > On Wed, 27 Apr 2005 13:34:13 -0000, tah2k wrote:
> >
> > I saw the same thing when I was evaluating the 2138. I was told
by the
> > Phillips FAE to use external pull-ups when the I/O pin is
configured
> > as an output. The internal weak pull-up works fine when the I/O
is
> > configured as an input.
> >
> >
> > --- In lpc2000@lpc2..., "dimed77" <dimed77@y...> wrote:
> > >
> > > Hi,
> > >
> > > Does the LPC2138 P0.10 pin have special electrical specs.?
When
> > > configured as GPIO, it goes to only 2V when in logic '1'
output, no
> > > load. Tried with 2 different chips already.
> > > Could someone give me a hint?
> > >
> > > Thanks :)
> > >
> > > Di > ---------------------------------
> Yahoo! Groups Links
>
> To > __________________________________________________
>
