D60C and D60P availability?

Started by James M. Knox December 3, 2003

We've been using the D60A (80QFP) in most of our recent designs. We are
now looking at redesigning an older product that uses the 912B32 to use
something more modern - probably the D60A or similar. The only thing I do
NOT like about the D60A is the oscillator circuit - we've been using an
external oscillator to get 16 MHz and (more importantly) reliable startup -
at the cost of higher current and dollars.

So I figured I would look at the D60P or maybe D60C, both of which appear
to offer 16 MHz operation and a more reliable oscillator circuit.

Trouble is... I can't seem to find them for sale. All the distributors
only have the 60A (at least, that's all they KNOW that they have). Even
the Motorola web site doesn't show that you can order anything but the A part.

Something obvious I am missing? Are the C and P parts only available
direct from Motorola in OEM quantities?

tnx, jmk

-----------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------



At 06:49 PM 12/4/2003 +0100, you wrote:
>
>Therefore I suggested to use a 8MHz crystal and the PLL (to get 8MHz
>E clock).
>
>BTW: Although the docs suggest not to use the PLL clock for CAN
>because it could have too much jitter, I don't believe that this
>warning is well-founded.

I don't have any need/use for CAN, so that's not an issue. And I do like
the PLL for the ability to change the operating frequency on the fly (to
reduce power consumption). However, I am not impressed with my own ability
to get PLL to reliably work without frequency drift over the full -40C to
+125C operating temperature range. [Some bad experiences some years ago.
<G>] Maybe that means it's time to make a few prototypes and put them in
the chamber.

Thanks for the info...
jmk

-----------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------



James M. Knox wrote:

> We've been using the D60A (80QFP) in most of our recent designs. We are
> now looking at redesigning an older product that uses the 912B32 to use
> something more modern - probably the D60A or similar. The only thing I do
> NOT like about the D60A is the oscillator circuit - we've been using an
> external oscillator to get 16 MHz and (more importantly) reliable startup -
> at the cost of higher current and dollars.

Use the D60A with a 8MHz crystal and PLL and a external reset with
delay (*809 and similar) => cheap and reliable.

Wrong pulses from the wimpy (sorry) D60A oscillator (observed during
fast transients, ESD tests) don't cause "code runaway" anymore
because the PLL doesn't follow them.

Oliver
--
Oliver Betz, Muenchen



At 10:17 AM 12/4/2003 +0100, you wrote:

>Use the D60A with a 8MHz crystal and PLL and a external reset with
>delay (*809 and similar) => cheap and reliable.
>
>Wrong pulses from the wimpy (sorry) D60A oscillator (observed during
>fast transients, ESD tests) don't cause "code runaway" anymore
>because the PLL doesn't follow them.

I thought the PLL wouldn't let you run at 16 MHz on the D60A. Obviously I
need to go back and check the latest updates to the datasheet.

jmk -----------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------



James M. Knox wrote:

[...]

> I thought the PLL wouldn't let you run at 16 MHz on the D60A. Obviously I

The max. bus clock is 8MHz, with or without the PLL.

> need to go back and check the latest updates to the datasheet.

This spec didn't change.

It might take a while until you find all the information about the
PLL in the "technical data", but besides the documentation it's
simple.

Oliver
--
Oliver Betz, Muenchen



At 04:34 PM 12/4/2003 +0100, you wrote:

> > I thought the PLL wouldn't let you run at 16 MHz on the D60A. Obviously I
>
>The max. bus clock is 8MHz, with or without the PLL.

Okay... poor choice of words. I thought the max clock (not E-clock) speed
with crystal or resonator for the 60A was only 8 - 10 MHz. Whereas with an
external oscillator I can run at 16 MHz. In fact I am pretty sure there
was quite a bit of discussion on this list about it a year or so ago...
including that there was an incorrect and/or misleading entry in the
datasheet that Motorola was going to (and did) change.

Am I wrong? [Sure wouldn't be the first time.]

jmk -----------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------



James M. Knox wrote:

> > > I thought the PLL wouldn't let you run at 16 MHz on the D60A. Obviously I
> >
> >The max. bus clock is 8MHz, with or without the PLL.
>
> Okay... poor choice of words. I thought the max clock (not E-clock) speed
> with crystal or resonator for the 60A was only 8 - 10 MHz. Whereas with an

Therefore I suggested to use a 8MHz crystal and the PLL (to get 8MHz
E clock).

BTW: Although the docs suggest not to use the PLL clock for CAN
because it could have too much jitter, I don't believe that this
warning is well-founded. CAN is quite robust against small amounts of
jitter, and my own jitter measurements showed no alarming deviation,
you should find my mail about this in the group archive.

BTW2: I wouldn't use a slower crystal because the BDM starts with
this frequency, and many BDM interfaces are not able to use the PLL.

Oliver
--
Oliver Betz, Muenchen



James M. Knox wrote:

[...]

> reduce power consumption). However, I am not impressed with my own ability
> to get PLL to reliably work without frequency drift over the full -40C to

PLL: phase _locked_ loop. If it works, it's as stable as your
reference frequency (crystal).

Oliver
--
Oliver Betz, Muenchen


Oliver
It appears as though you are suggesting that in ANY harsh environment
the PLL is necessary for the D60a. So, for my application, using an
8Mhz crystal (and thus a 4 mhz bus speed) to duplicate this using a PLL
I would need to let SYNC=0 and REFDIV=1. Of course, this is purely
academic since our boards are already designed without the PLL, but for
future reference....the S12 PLL filter calculator program yields
series resistance0 ohm
series capacitance3nf
parallel capacitance=3.3 nf

will these values work for the D60a as well? I can't seem to find a
calculator program for the D60a.

Stewart Prince
Professor, Mech Eng
CSUN

Oliver Betz wrote:

>James M. Knox wrote: >
>>>>I thought the PLL wouldn't let you run at 16 MHz on the D60A. Obviously I
>>>>
>>>>
>>>The max. bus clock is 8MHz, with or without the PLL.
>>>
>>>
>>Okay... poor choice of words. I thought the max clock (not E-clock) speed
>>with crystal or resonator for the 60A was only 8 - 10 MHz. Whereas with an
>>
>>
>
>Therefore I suggested to use a 8MHz crystal and the PLL (to get 8MHz
>E clock).
>
>BTW: Although the docs suggest not to use the PLL clock for CAN
>because it could have too much jitter, I don't believe that this
>warning is well-founded. CAN is quite robust against small amounts of
>jitter, and my own jitter measurements showed no alarming deviation,
>you should find my mail about this in the group archive.
>
>BTW2: I wouldn't use a slower crystal because the BDM starts with
>this frequency, and many BDM interfaces are not able to use the PLL.
>
>Oliver



Hi All,

To pursue the tangential point further on PLL stability:-

> > reduce power consumption). However, I am not impressed with my own
ability
> > to get PLL to reliably work without frequency drift over the full -40C
to
>
> PLL: phase _locked_ loop. If it works, it's as stable as your
> reference frequency (crystal).

Certainly the frequency is going to be fine with a pll, but I once looked at
the jitter by triggering an oscilloscope on the PLL output of a MC68HC16,
and found the PLL slowly drifted back and forth a cycle or two after a few
10's of mS delay from the trigger, but a crystal would not drift in that
way. This is an excellent performance given that the starting frequency was
32KHz and the output 16MHz. I have not tried the same experiment with a
PowerPC or HCS12, which in my application have much lower multiplication
factors. Andrew Lohmann AIIE
Design Engineer

Bellingham + Stanley Ltd.
Longfield Road, Tunbridge Wells, Kent, TN2 3EY, England.
Tel: +44 (0) 1892 500400
Fax: +44 (0) 1892 543115
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