Eeprom in 16F648A

Started by wantoniet March 14, 2004
Hi,

I was working at my last project and found a problem so very
interesting. My equipament used a 16f628 and i upgraded to 16f648a
cause i required more flash memory. On step to write in internal
eeprom, i realized that sometimes wrote right, sometimes not. After
two days of hard debug and exaustive work i discovered that this
chip got a bug. Microchips errata indicate to put it in sleep mode
every time you want write eeprom...

I am advincing anyone that think to use 16f648a. Be careful, so!!!

The link to comprove the error:
http://www.microchip.com/1010/pline/picmicro/category/embctrl/8kbytes
/devices/16f648a/10959/

Regards,



Wow, that sucks. Hopefully they are delivering good stuff now.
Actual link is:
http://www.microchip.com/download/lit/suppdoc/errata/80151g.pdf

--- wantoniet <> wrote:
> Hi,
>
> I was working at my last project and found a problem so very
> interesting. My equipament used a 16f628 and i upgraded to 16f648a
> cause i required more flash memory. On step to write in internal
> eeprom, i realized that sometimes wrote right, sometimes not. After
> two days of hard debug and exaustive work i discovered that this
> chip got a bug. Microchips errata indicate to put it in sleep mode
> every time you want write eeprom...
>
> I am advincing anyone that think to use 16f648a. Be careful, so!!!
>
> The link to comprove the error:
> http://www.microchip.com/1010/pline/picmicro/category/embctrl/8kbytes
> /devices/16f648a/10959/
>
> Regards, >


=====
My software has no bugs. Only undocumented features.

__________________________________





How can I tell the silicon revision of the chip I'm using?

-----Original Message-----
From: Chad Russel [mailto:]
Sent: Sunday, March 14, 2004 10:25 AM
To:
Subject: Re: [piclist] Eeprom in 16F648A Wow, that sucks. Hopefully they are delivering good stuff now.
Actual link is:
http://www.microchip.com/download/lit/suppdoc/errata/80151g.pdf

--- wantoniet <> wrote:
> Hi,
>
> I was working at my last project and found a problem so very
> interesting. My equipament used a 16f628 and i upgraded to 16f648a
> cause i required more flash memory. On step to write in internal
> eeprom, i realized that sometimes wrote right, sometimes not. After
> two days of hard debug and exaustive work i discovered that this
> chip got a bug. Microchip4s errata indicate to put it in sleep mode
> every time you want write eeprom...
>
> I am advincing anyone that think to use 16f648a. Be careful, so!!!
>
> The link to comprove the error:
> http://www.microchip.com/1010/pline/picmicro/category/embctrl/8kbytes
> /devices/16f648a/10959/
>
> Regards, >


=====
My software has no bugs. Only undocumented features.

__________________________________

to unsubscribe, go to http://www.yahoogroups.com and follow the instructions
Yahoo! Groups Links



--- In , "wantoniet" <engenharia3@c...> wrote:
> chip got a bug. Microchips errata indicate to put it in sleep mode
> every time you want write eeprom...

First rule of hardware -- always look at the errata before using it.
Hardware has always got problems. Typically they involves corner
cases that don't affect most people and may go bascically
undiscovered but once in a while there is a good one.


--- In , "Bert Drake" <Bert@D...> wrote:
> How can I tell the silicon revision of the chip I'm using?

I think it is generally, if not always, stored with the chip ID in
the config space. At least it is in the 18 series chips I typically
use. You can read it using a TBLRD instruction as per the datasheet.


You know that is a very good question. Some of the errata sheets list
date codes.

I just checked my email updates and found the same problem on 16F627A
of which I just received another 100 on Friday with date code 0337.
Fortunately I am not using the EEPROM. I will call Microchip tomorrow
and report back.

You can probably be certain yours are affected if the part date code is
before the Errata Date.

Chad

--- Bert Drake <> wrote:
> How can I tell the silicon revision of the chip I'm using?
>
> -----Original Message-----
> From: Chad Russel [mailto:]
> Sent: Sunday, March 14, 2004 10:25 AM
> To:
> Subject: Re: [piclist] Eeprom in 16F648A > Wow, that sucks. Hopefully they are delivering good stuff now.
> Actual link is:
> http://www.microchip.com/download/lit/suppdoc/errata/80151g.pdf
>
> --- wantoniet <> wrote:
> > Hi,
> >
> > I was working at my last project and found a problem so very
> > interesting. My equipament used a 16f628 and i upgraded to 16f648a
> > cause i required more flash memory. On step to write in internal
> > eeprom, i realized that sometimes wrote right, sometimes not. After
> > two days of hard debug and exaustive work i discovered that this
> > chip got a bug. Microchip4s errata indicate to put it in sleep mode
> > every time you want write eeprom...
> >
> > I am advincing anyone that think to use 16f648a. Be careful, so!!!
> >
> > The link to comprove the error:
> >
> http://www.microchip.com/1010/pline/picmicro/category/embctrl/8kbytes
> > /devices/16f648a/10959/
> >
> > Regards,
> >
> >
> > =====
> My software has no bugs. Only undocumented features.
>
> __________________________________
> >
> to unsubscribe, go to http://www.yahoogroups.com and follow the
> instructions
> Yahoo! Groups Links >


=====
My software has no bugs. Only undocumented features.

__________________________________