uP/uC Floating Pins?

Michael A. Terrell
Guest

Fri Mar 12, 2010 12:55 am

Hal Murray wrote:

Quote:

Read the data sheet.

What if it hasn't been written yet?

Why are you designing something for a chip that doesn't exist?

Ask the guy who is trying to sell you the chip?
Ask the guy who told you about the chip?
Use another chip.

Jim designs chips. There are no data sheets until the designs are
complete.

--
Lead free solder is Belgium's version of 'Hold my beer and watch this!'

Jim Thompson
Guest

Fri Mar 12, 2010 1:04 am

On Thu, 11 Mar 2010 18:55:21 -0500, "Michael A. Terrell"
<mike.terrell_at_earthlink.net> wrote:

Quote:

Hal Murray wrote:

Read the data sheet.

What if it hasn't been written yet?

Why are you designing something for a chip that doesn't exist?

Ask the guy who is trying to sell you the chip?
Ask the guy who told you about the chip?
Use another chip.

Jim designs chips. There are no data sheets until the designs are
complete.

I don't design uP's or uC's, at least not complete ones... small local
controls, occasionally.

Here I have a analog situation where a floating input can cause high
currents (like 250mA) to flow, so I just wanted to make sure it was a
real problem before I added-in a fix. It's done, took me 4 MOS
transistors Smile

Michael A. Terrell
Guest

Fri Mar 12, 2010 6:03 am

Jim Thompson wrote:

Quote:

On Thu, 11 Mar 2010 18:55:21 -0500, "Michael A. Terrell"
mike.terrell_at_earthlink.net> wrote:

Hal Murray wrote:

Read the data sheet.

What if it hasn't been written yet?

Why are you designing something for a chip that doesn't exist?

Ask the guy who is trying to sell you the chip?
Ask the guy who told you about the chip?
Use another chip.

Jim designs chips. There are no data sheets until the designs are
complete.

I don't design uP's or uC's, at least not complete ones... small local
controls, occasionally.

Here I have a analog situation where a floating input can cause high
currents (like 250mA) to flow, so I just wanted to make sure it was a
real problem before I added-in a fix. It's done, took me 4 MOS
transistors Smile

I thought you had done some analog parts of ASIC that had a stock CPU
design?

--
Lead free solder is Belgium's version of 'Hold my beer and watch this!'

Clint Sharp
Guest

Mon Mar 15, 2010 8:40 pm

In message <4B9982E9.7EFAA382_at_earthlink.net>, Michael A. Terrell
<mike.terrell_at_earthlink.net> writes

Quote:

Jim designs chips. There are no data sheets until the designs are
complete.
Yeah, but in this case, he's designing what sounds like a peripheral for

an existing chip. If it was a design of Jim's then I'd not have expected
him to need to ask the question.

Quote:

--
Clint Sharp

Jim Thompson
Guest

Mon Mar 15, 2010 9:01 pm

On Mon, 15 Mar 2010 19:40:55 +0000, Clint Sharp
<clint_at_clintsmc.demon.co.uk> wrote:

Quote:

In message <4B9982E9.7EFAA382_at_earthlink.net>, Michael A. Terrell
mike.terrell_at_earthlink.net> writes
Jim designs chips. There are no data sheets until the designs are
complete.
Yeah, but in this case, he's designing what sounds like a peripheral for
an existing chip. If it was a design of Jim's then I'd not have expected
him to need to ask the question.

Ever hear of flaky (*) customers? Many weird, non-physical requests
and lots of misinformation. So I ask here to get the true scoop :-)

* Like a customer who labels the R and C for a triangle wave
oscillator on his "specification" as "TANK1" and "TANK2"... I kid you
not Sad