Crystal Speed For PIC

Started by techy fellow November 12, 2003
Hi,
 
I came across a project that requires a 16F84/P-10 and a 10 Mhz crystal. I do not have any 16F84/P-10 but, I do have 16F84/P-20. Can I substitute 16F84/P-10 with the -20 part and still use the 10Mhz crystal ?
 
Thanks in advance for the help.
Davis



Yes

techy fellow wrote:

 Hi, I came across a project that requires a 16F84/P-10 and a 10 Mhz crystal. I do not have any 16F84/P-10 but, I do have 16F84/P-20. Can I substitute 16F84/P-10 with the -20 part and still use the 10Mhz crystal ? Thanks in advance for the help.Davis

P-10 or P-20 is just an indication of the maximum
frequency. Lower frequencies are allways possible.

Kees

--- techy fellow <> wrote:
> Hi,
>
> I came across a project that requires a 16F84/P-10
> and a 10 Mhz crystal. I do not have any 16F84/P-10
> but, I do have 16F84/P-20. Can I substitute
> 16F84/P-10 with the -20 part and still use the 10Mhz
> crystal ?
>
> Thanks in advance for the help.
> Davis > ---------------------------------
>
__________________________________




Thanks alot for the info, guys. Moving forward, since higher speed MCUs can run at lower frequency, I'll buy MCUs at highest available speed.
 
cheers,
Davis

Kees Stenekes <k...@yahoo.com> wrote:
P-10 or P-20 is just an indication of the maximum
frequency. Lower frequencies are allways possible.

Kees

--- techy fellow <t...@yahoo.com> wrote:
> Hi,

> I came across a project that requires a 16F84/P-10
> and a 10 Mhz crystal. I do not have any 16F84/P-10
> but, I do have 16F84/P-20. Can I substitute
> 16F84/P-10 with the -20 part and still use the 10Mhz
> crystal ?

> Thanks in advance for the help.
> Davis> ---------------------------------
>
__________________________________


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You have to keep in mind that if and when you run at a higher speed it
will draw slightly more current, and the cost of higher speed devices is
greater.
Rick

techy fellow wrote:

> Thanks alot for the info, guys. Moving forward, since higher speed
> MCUs can run at lower frequency, I'll buy MCUs at highest available
> speed. cheers,Davis
>
> Kees Stenekes <> wrote:
>
> P-10 or P-20 is just an indication of the maximum
> frequency. Lower frequencies are allways possible.
>
> Kees
>
> --- techy fellow <> wrote:
> > Hi,
> >
> > I came across a project that requires a 16F84/P-10
> > and a 10 Mhz crystal. I do not have any 16F84/P-10
> > but, I do have 16F84/P-20. Can I substitute
> > 16F84/P-10 with the -20 part and still use the 10Mhz
> > crystal ?
> >
> > Thanks in advance for the help.
> > Davis
> >
> >
>

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>
> to unsubscribe, go to http://www.yahoogroups.com and follow
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The F84 is an awfully old part. Unless its for a canned design with
firmware you dont want to touch, you might want to look at the
16F628A. Lots more of everything, 20 Mhz and cheaper than the 84s...

--- In , techy fellow <techyf@y...> wrote:
> Thanks alot for the info, guys. Moving forward, since higher speed
MCUs can run at lower frequency, I'll buy MCUs at highest available
speed.
>
> cheers,
> Davis
>
> Kees Stenekes <knalkeez@y...> wrote:
> P-10 or P-20 is just an indication of the maximum
> frequency. Lower frequencies are allways possible.
>
> Kees
>
> --- techy fellow <techyf@y...> wrote:
> > Hi,
> >
> > I came across a project that requires a 16F84/P-10
> > and a 10 Mhz crystal. I do not have any 16F84/P-10
> > but, I do have 16F84/P-20. Can I substitute
> > 16F84/P-10 with the -20 part and still use the 10Mhz
> > crystal ?
> >
> > Thanks in advance for the help.
> > Davis
> >
> >
> > ---------------------------------
> >
> __________________________________ >
> to unsubscribe, go to http://www.yahoogroups.com and follow the
instructions
>
> Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.
>
>
> ---------------------------------
>



> The F84 is an awfully old part. Unless its for a canned design with
> firmware you dont want to touch, you might want to look at the
> 16F628A. Lots more of everything, 20 Mhz and cheaper than the 84s...

And if you are (re)doing a design consider the dirt-cheap 14-pin 16F630.
Even the version with A/D (16F676) is cheaper than a 16F628A. An it
provides 8 A/D inputs, which is more than the 28-pin PICs have!

Wouter van Ooijen

-- -------
Van Ooijen Technische Informatica: www.voti.nl
consultancy, development, PICmicro products


Yep ! I agreed with you wholeheartedly, Phil. I only stocked up minimal quantities of F84A parts (I've 5 pcs). This is because I am a newbie in electronics and I build projects based on magazines (eg. Elektor, EPE, Nuts&Volts and Circuit Cellars). When the project uses 16F84(A) part, I will have to use the same model else, the codes that comes with it will not work with say, 16F628(A).
 
In fact, I faced lots of problems trying to buy small quantity for MCUs. I'm sure some of you out there is facing the same problem. Just to quote you an example, I bought 18 pcs of 16F628 (std MOQ per tube) but found out that 16F628A was available (bought another 5 pcs). The problem I am facing is, I can't just buy one piece, no one will want to sell just one piece to me in Singapore. After sourcing and bargaining, I ended up with a deal buying at least 5 pcs per model. Over time, I've parts like 12C508A, 12C509A, 24LC256, 24LC512, 16F628, 16F628A, 16F84A, 16F877, 18F248, 18F452 and AVR ATtiny12, AT90S1200, 2313, 8515, 8535, ATMega 64 and 128. 8051 family - AT89C2051 and AT89C4051. A bunch of I2C chips PCF84. All at the highest available speed and industrial grade (some commercial grade).
 
I'm sure some of the above MCUs are already outdated and replaced by enhanced model (eg. AT90S2313 replaced by ATtiny2313). But, as always, I looked at it from the bright side, at least, I have a source who is willing to supply different models and brands of MCUs at 5 pieces MOQ so to speak. Hum... come to think about it, I can do business by selling 1 piece of each model (in a package of minimum 10 models) to hobbysts. Hobbyists will be happy cos' get to sample different models with minimal fuss and costs and I can earn some money to fund my hobby. Anyone from Singapore interested in buying from me ??
 
cheers,
Davis

Phil <p...@yahoo.com> wrote:
The F84 is an awfully old part.  Unless its for a canned design with
firmware you dont want to touch, you might want to look at the
16F628A.  Lots more of everything, 20 Mhz and cheaper than the 84s...

--- In p...@yahoogroups.com, techy fellow <techyf@y...> wrote:
> Thanks alot for the info, guys. Moving forward, since higher speed
MCUs can run at lower frequency, I'll buy MCUs at highest available
speed.

> cheers,
> Davis
>
> Kees Stenekes <knalkeez@y...> wrote:
> P-10 or P-20 is just an indication of the maximum
> frequency. Lower frequencies are allways possible.
>
> Kees
>
> --- techy fellow <techyf@y...> wrote:
> > Hi,
> > 
> > I came across a project that requires a 16F84/P-10
> > and a 10 Mhz crystal. I do not have any 16F84/P-10
> > but, I do have 16F84/P-20. Can I substitute
> > 16F84/P-10 with the -20 part and still use the 10Mhz
> > crystal ?
> > 
> > Thanks in advance for the help.
> > Davis
> >
> >
> > ---------------------------------
> >
> __________________________________>
> to unsubscribe, go to http://www.yahoogroups.com and follow the
instructions
>
> ">Yahoo! Terms of Service.