Post by thread:[PIC]: 16F674 hex code onto 16F677

Hi all I am helping a friend with a hobby project. He send me a hex file for 16F674 (4K) but I only have 16F677 (8K) in stock. I never worked with hex files before (except upgrading picstart), so my question is: What do I have to do (if any) to put the code on a 16f677? In case you were wondering where the code comes from: gm.cnc.free.fr OR http://www.rc-aero.net I don't really want to waste time disasembling the code. (Would be quicker to go and buy a 16F674). Quentin spam_OUTqscTakeThisOuTiptech.co.za http://www.iptech.co.za -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Depends a lot on how the code is written - it may just run, but if it uses banked vars in the upper common area it will fall over. On Thu, 20 Mar 2003 12:59:54 +0200, you wrote: {Quote hidden}>Hi all >I am helping a friend with a hobby project. He send me a hex file for >16F674 (4K) but I only have 16F677 (8K) in stock. I never worked with >hex files before (except upgrading picstart), so my question is: What do >I have to do (if any) to put the code on a 16f677? > >In case you were wondering where the code comes from: >gm.cnc.free.fr >OR >http://www.rc-aero.net > >I don't really want to waste time disasembling the code. (Would be >quicker to go and buy a 16F674). > > >Quentin >.....qscKILLspam@spam@iptech.co.za >http://www.iptech.co.za -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

> I am helping a friend with a hobby project. He send me a hex file for > 16F674 (4K) but I only have 16F677 (8K) in stock. I never worked with > hex files before (except upgrading picstart), so my question is: What do > I have to do (if any) to put the code on a 16f677? He is either mistaken or just sent you to fetch a #5 skyhook. My line card shows no such thing as a PIC 16F674 or 16F677, even the vaporware section. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

I'm doing some development for a client using an 16F876, but he is using an 872. I tried the 872 hex file on the 876 and it does NOT work. The only obvious difference in the two chips is the 876 has more memory. At 04:27 PM 3/20/2003 +0200, you wrote: {Quote hidden}>Sooorry!!! >Let me pick my brain up from the floor... :) >16F874 and 877 >Anyway, I loaded it on a 877 and will see tonight if it works. >>#5 skyhook >No, but I would like a bottle of 5A Blue current! >(old joke we played on the aprentices) > >-- >Quentin >.....qscKILLspam.....iptech.co.za >http://www.iptech.co.za > >-- >http://www.piclist.com hint: The PICList is archived three different >ways. See http://www.piclist.com/#archives for details. Larry Bradley Orleans (Ottawa), Ontario, CANADA -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

On Thu, 20 Mar 2003 09:48:04 -0500, you wrote: >I'm doing some development for a client using an 16F876, but he is using an >872. I tried the 872 hex file on the 876 and it does NOT work. The only >obvious difference in the two chips is the 876 has more memory. There are some less obvious differences, in partictular the top area of RAM is shared across all banks, where the lower-end parts have completely seperate banks. There is also an extra program memory page preselect bit, but this would not normally cause a problem. {Quote hidden}>At 04:27 PM 3/20/2003 +0200, you wrote: >>Sooorry!!! >>Let me pick my brain up from the floor... :) >>16F874 and 877 >>Anyway, I loaded it on a 877 and will see tonight if it works. >>>#5 skyhook >>No, but I would like a bottle of 5A Blue current! >>(old joke we played on the aprentices) >> >>-- >>Quentin >>EraseMEqscspam_OUTTakeThisOuTiptech.co.za >>http://www.iptech.co.za >> >>-- >>http://www.piclist.com hint: The PICList is archived three different >>ways. See http://www.piclist.com/#archives for details. > >Larry Bradley >Orleans (Ottawa), Ontario, CANADA -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

I've developed a project on 16F876 and then changed it to a 870 for production. All I had to do was change the type and the header. But I must say I did develop the code to be used on an 870 eventually. Still, what I want to do is the other way around so let's see. I see some banking but it looks like it is mostly for the FSR's. The code is a bit difficult to read as it was not written with assembler. (If you want to see how much code space and time programming with C or Basic waste, dissasemble the hex file.) > I'm doing some development for a client using an 16F876, but he is using an > 872. I tried the 872 hex file on the 876 and it does NOT work. The only > obvious difference in the two chips is the 876 has more memory. -- Quentin qscspam_OUTiptech.co.za http://www.iptech.co.za -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

> -----Original Message----- > From: Quentin [SMTP:@spam@qscKILLspamIPTECH.CO.ZA] > Sent: Thursday, March 20, 2003 3:45 PM > To: KILLspamPICLISTKILLspamMITVMA.MIT.EDU > Subject: Re: [PIC]: 16F674 hex code onto 16F677 > > I see some banking but it looks like it is mostly for the FSR's. The > code is a bit difficult to read as it was not written with assembler. > (If you want to see how much code space and time programming with C or > Basic waste, dissasemble the hex file.) > The reason it's not very readable is that compilers can use tricks to optimise code that would not be easily understandable or maintainable in ASM. The code produced by the popular PIC c compilers is actually very good in most circumstances. 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 RemoveMEpostmasterTakeThisOuTbookham.com. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

> Anyway, I loaded it on a 877 and will see tonight if it works. It may not work. The 16F874 has unique RAM at F0h - FFh, whereas the 16F877 has this region aliased to 70h - 7Fh. If the code doesn't use RAM from F0h - FFh and doesn't screw eith the RP1 bit in STATUS (bad programming practise, but there seems to be no shortage of bad programmers), it should work. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

On Thu, 20 Mar 2003, Michael Rigby-Jones wrote: > The reason it's not very readable is that compilers can use tricks to > optimise code that would not be easily understandable or maintainable in > ASM. The code produced by the popular PIC c compilers is actually very good > in most circumstances. *IF* the programmer understands the PIC and the compiler. I've put a lot of time into my most recent project just going through the asm listing produced by the compiler, looking for ways to write better C code to produce more compact assembly code. If you write C just like for a system where there are virtually no resource limits, you'll get correspondingly inefficient code. Dale -- It's a thankless job, but I've got a lot of Karma to burn off. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

First, the 877 works, thanks all! But I am still going to get him an 874. > The reason it's not very readable is that compilers can use tricks to > optimise code that would not be easily understandable or maintainable in > ASM. The code produced by the popular PIC c compilers is actually very good > in most circumstances. I am not just talking about the readability, but the waste of program space and execution time. The code is full of the following for example: BTFSS some_bit GOTO A GOTO B A GOTO C ;Or Somewhere_else B GOTO Anada_place C GOTO Anada_nada_place ;Sometimes this line is also here for ;some reason. That is a lot of GOTOs just to test a bit (between 3 to 5 GOTO's everytime). -- Quentin spamBeGoneqscspamBeGoneiptech.co.za http://www.iptech.co.za -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

> (between 3 to 5 GOTO's everytime). OK, Make that 7 GOTO's. Figure this one out (maybe it was just a bad program the guy was using): 062B btfss 0x5,0x5 062C goto 0x62F 062D goto 0x62E 062E goto 0x631 062F goto 0x630 0630 goto 0x626 0631 goto 0x633 0632 goto 0x633 0633 bsf 0x3,0x5 -- Quentin TakeThisOuTqscEraseMEspam_OUTiptech.co.za http://www.iptech.co.za -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

On Thursday 20 March 2003 11:49 am, Quentin wrote: {Quote hidden}> First, the 877 works, thanks all! But I am still going to get him > an 874. > > > The reason it's not very readable is that compilers can use > > tricks to optimise code that would not be easily understandable > > or maintainable in ASM. The code produced by the popular PIC c > > compilers is actually very good in most circumstances. > > I am not just talking about the readability, but the waste of > program space and execution time. > The code is full of the following for example: > BTFSS some_bit > GOTO A > GOTO B > > A GOTO C ;Or Somewhere_else > B GOTO Anada_place > C GOTO Anada_nada_place ;Sometimes this line is also here > for ;some reason. > That is a lot of GOTOs just to test a bit (between 3 to 5 GOTO's > everytime). Then you're using a poor compiler. As an example of what a decent compiler can do, here's some output from the Microchip C18 compiler (yes, I know this is a different family, but that doesn't matter for this code): 00090a a2ab BTFSS 0xab,0x1,0x0 if (RCSTAbits.OERR) // overrun? 00090c d004 BRA 0x916 { 00090e 98ab BCF 0xab,0x4,0x0 RCSTAbits.CREN = 0; // disable receiver 000910 88ab BSF 0xab,0x4,0x0 RCSTAbits.CREN = 1; // enable receiver 000912 8403 BSF 0x3,0x2,0x0 ISRFlags.overrunError = 1; } 000914 d01b BRA 0x94c else if (RCSTAbits.FERR) // framing error? now what? 000916 a4ab BTFSS 0xab,0x2,0x0 000918 d004 BRA 0x922 { uchar c; 00091a cfae MOVFF 0xfae,0xca c = RCREG; // just read bad byte 00091c f0ca 00091e 8603 BSF 0x3,0x3,0x0 ISRFlags.framingError = 1; } -- Ned Konz http://bike-nomad.com GPG key ID: BEEA7EFE -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

{Quote hidden}> -----Original Message----- > From: Dale Botkin [SMTP:RemoveMEdaleTakeThisOuTBOTKIN.ORG] > Sent: Thursday, March 20, 2003 4:30 PM > To: PICLISTEraseME.....MITVMA.MIT.EDU > Subject: Re: [PIC]: 16F674 hex code onto 16F677 > > On Thu, 20 Mar 2003, Michael Rigby-Jones wrote: > > > The reason it's not very readable is that compilers can use tricks to > > optimise code that would not be easily understandable or maintainable in > > ASM. The code produced by the popular PIC c compilers is actually very > good > > in most circumstances. > > *IF* the programmer understands the PIC and the compiler. I've put a lot > of time into my most recent project just going through the asm listing > produced by the compiler, looking for ways to write better C code to > produce more compact assembly code. If you write C just like for a system > where there are virtually no resource limits, you'll get correspondingly > inefficient code. > Absolutely. When I started using HiTech many years ago I spent considerable amounts of time looking at the ASM produced so that I could let the compiler produce the most efficient code. I know some people would regard this as a waste of time when they could achieve simmilar results in assembler, but once you've learnt a compilers habits you can start banging out pretty decent code much faster than an ASM programmer could. 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 EraseMEpostmasterbookham.com. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email RemoveMElistservEraseMEEraseMEmitvma.mit.edu with SET PICList DIGEST in the body