>Michael Rigby-Jones wrote:
>
>>>> It might do 40MHz, but it's rated as a 25MHz part along with the
>>>> rest of this particular sub-family including the 6620,6720
>and 8620.
>
>From: Jan-Erik Soderholm XA (TN/PAC)
>
>The 18F6xxx and 18F8xxx range has both 25 and 40 Mhz parts.
>Check the Line Card. Yes, you might find a "sub-sub-family"
>amongst those that are rated at either 25Mhz or 40Mhz, but I
>read your post as including all 18F6xxx and 18F8xxx parts.
>

The 18F6620, 18F6820, 18F6720 and 18F8720 are all members of one family
which is why one datasheet covers all these devices.

>>>> In fact even 25MHz is not reliably achievable on existing silicon,
>>>> the errata states that 4MHz is the maximum clock frequency
>to avoid
>>>> a bug that causes random corruption during the instruction fetch.
>
>What "errata" ?
>
>I have checked a three random errata sheets for the 18F6xxx
>and 18F8xxx range, and can not find that problem in any of them.
>
>Isn't the "4Mhz problem" an issue for the 18F1220 and friends ?

No, the errata also affected the early large memory parts, including the
whole sub-family I mentioned above.  Take a look at
http://www.microchip.com/download/lit/suppdoc/errata/80129g.pdf

Regards

Mike




=======================================================================
This e-mail is intended for the person it is addressed to only. The
information contained in it may be confidential and/or protected by
law. If you are not the intended recipient of this message, you must
not make any use of this information, or copy or show it to any
person. Please contact us immediately to tell us that you have
received this e-mail, and return the original to us. Any use,
forwarding, printing or copying of this message is strictly prohibited.
No part of this message can be considered a request for goods or
services.
=======================================================================
Any questions about Bookham's E-Mail service should be directed to
postmaster@bookham.com.

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.