Maybe. Take into account that MCS51 OTP processors usually are 8K of code. I use, among the others, the AT89C55 that has 20K of flash ROM. It seems better to use a ROMless 8051 and place the code/tables in the PSD.
On Fri, Feb 17, 2012 at 6:17 PM, Bob Camp <li...@rtty.us> wrote: > Hi > > I'd bet that there's some code in there and some data tables. Without > digging in, it's hard to say how big each is. We could easily find that > there's 24K of code in the MCS51 and a bunch of tables in the PSD813. > > Bob > > -----Original Message----- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Azelio Boriani > Sent: Friday, February 17, 2012 6:06 AM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] FE-5680A firmware dump > > OK, then maybe there are ROM bank switching as the MCS51 can't execute > beyon the 64K limit. It can be very challenging to follow a code that jumps > between 64K ROM banks. Moreover the MCS51 has to address the external RAM > by massive pointer use (the famous MOVX @DPTR,A and MOVX A,@DPTR > instructions) beyond the 256byte internal easier to address RAM. Yes, you > need a good disassembler, aware of bank switching and massive pointer use. > > On Fri, Feb 17, 2012 at 11:20 AM, Javier Herrero > <jherr...@hvsistemas.es>wrote: > > > Don forget the PSD813 :) It provides 128KB Flash and 8KB RAM... so it can > > be a bit more complicated > > > > Regards, > > > > Javier > > > > El 17/02/2012 11:09, Azelio Boriani escribió: > > > >> In my opinion you don't need the power of an IDA-class disassembler to > >> process an 8051-like code. The MCS51 family processors have only 128 or > >> 256 > >> bytes of RAM (and at most 64K ROM) and cannot host complex code. > >> > >> On Fri, Feb 17, 2012 at 10:27 AM, Elio Corbolante<elio...@gmail.com> > >> wrote: > >> > >> From: Mike McCauley > >>> > >>>> I've been considering ripping the firmware from the mcu as well. I've > >>>>>> > >>>>> not > >>> > >>>> got beyond the consideration stages, but i have all the equipment here > >>>>>> > >>>>> at > >>> > >>>> work. When you say that the read option is not available. is this > >>>>>> > >>>>> because > >>> > >>>> the chip has protection fuses enabled? > >>>>>> > >>>>> Id like to help with the disassembly if you can get the binary dump. > >>>> > >>> > >>> Don't worry: when I will be able to dump the firmware I will let it on > >>> the > >>> public domain. > >>> BTW, I have the opportunity to use the IDA disassembler (a friend of > mine > >>> is a licensed user) so I think the disassembly of the code will be > rather > >>> good. > >>> Any knowledge of a public domain 8051 disassembler which can rival IDA > in > >>> performance/code analysis? > >>> > >>> _ Elio. > >>> ______________________________**_________________ > >>> time-nuts mailing list -- time-nuts@febo.com > >>> To unsubscribe, go to > >>> > https://www.febo.com/cgi-bin/**mailman/listinfo/time-nuts< > https://www.febo.c > om/cgi-bin/mailman/listinfo/time-nuts> > >>> and follow the instructions there. > >>> > >>> ______________________________**_________________ > >> time-nuts mailing list -- time-nuts@febo.com > >> To unsubscribe, go to https://www.febo.com/cgi-bin/** > >> > mailman/listinfo/time-nuts< > https://www.febo.com/cgi-bin/mailman/listinfo/tim > e-nuts> > >> and follow the instructions there. > >> > >> > >> > > ______________________________**_________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to https://www.febo.com/cgi-bin/** > > > mailman/listinfo/time-nuts< > https://www.febo.com/cgi-bin/mailman/listinfo/tim > e-nuts> > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.