89C51ED2
in [Design]
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From: Joerg on 6 Sep 2008 11:34 Eeyore wrote: > > Joerg wrote: > >> Rich Grise wrote: >>> On Fri, 05 Sep 2008 17:53:59 +0100, TT_Man wrote: >>>> ">> >>>>>>>> I think he said it was all written in asssembler <yuk>. >>>>>>> On an 8051, asm is really the way to go. The OP was making comments >>>>>>> about DPTR so I suspected asm but vagueness of his descriptions >>>>>>> sounded like a C programmer who doesn't really know what is going on >>>>>>> under the hood. Many C compilers overlay variables on the 8051 if he >>>>>>> is doing interrupts in C code he may be running a routine in the >>>>>>> interrupt code that overlays one of his variables. >>>>>> Not a prayer in hell 100% assembler. :) >>>>> Are you using interrupts? >>>> Everything is interrupt driven. Processor spends 99% in sleep mode.Int >>>> routines set flags and the background processes flags, then goes back to >>>> sleep. Dual 3 of 5 uarts are processed with 125uS RTC. >>> This raises a BIG red flag for me - how long does the uP take to come out >>> of sleep mode? How's the interrupt latency? Did it used to block other >>> interrupts, or could they be stepping on each other? >> This is done all the time. First time I used the PCON features on a >> 88C51 was in the early 90's. You have to make sure it does a controlled >> wake up (socks, shoes, brush teeth, etc.) and know the time it takes. >> When you build analog/RF stuff where there needs to be radio silence >> you've got no other choice. > > And IIRC, the recent iterations of 8051 variants have improved the sleep etc > function. It used to be almost useless. > It was not useless. I sucessfully used it in the early 90's and that one is still in production. Same code as the old code. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: legg on 6 Sep 2008 12:06 On Thu, 04 Sep 2008 14:29:05 +0100, Eeyore <rabbitsfriendsandrelations(a)hotmail.com> wrote: > > >MooseFET wrote: > >> Is it written in ASM or C? > >I think he said it was all written in asssembler <yuk>. Can't think of a more apt instance where assembler shows it's advantages over more bloated forms - in troubleshooting IC abnormal behavior at a specific stage of operation. RL
From: Eeyore on 6 Sep 2008 12:43 Joerg wrote: > JosephKK wrote: > > Joerg wrote: > >> > >> Well! 40 years is a respectable life for a car. > > > > It certainly is. Question: Are there any current electronic parts, > > resistors, capacitors, inductors, diodes, transistors or ICs that have > > been available for 40 years. > > Tons of them. I design with them every day. LM324, 2N2222, 2N3904, > uA-whatever, LM331, LM339 and so on. Isn't the 2N2222 in metal can a little pricey for you ? Surely you mean the PN2222 ? Fortunately Pro-Electron didn't make numbering mistakes like that. The metal can BC108 of old is now the BC548 in TO-92 and probably much improved specs too. Graham
From: Eeyore on 6 Sep 2008 12:45 Joerg wrote: > Eeyore wrote: > > Joerg wrote: > >> Rich Grise wrote: > >>> TT_Man wrote: > >>>> ">> > >>>>>>>> I think he said it was all written in asssembler <yuk>. > >>>>>>> On an 8051, asm is really the way to go. The OP was making comments > >>>>>>> about DPTR so I suspected asm but vagueness of his descriptions > >>>>>>> sounded like a C programmer who doesn't really know what is going on > >>>>>>> under the hood. Many C compilers overlay variables on the 8051 if he > >>>>>>> is doing interrupts in C code he may be running a routine in the > >>>>>>> interrupt code that overlays one of his variables. > >>>>>> Not a prayer in hell 100% assembler. :) > >>>>> Are you using interrupts? > >>>> Everything is interrupt driven. Processor spends 99% in sleep mode.Int > >>>> routines set flags and the background processes flags, then goes back to > >>>> sleep. Dual 3 of 5 uarts are processed with 125uS RTC. > >>> This raises a BIG red flag for me - how long does the uP take to come out > >>> of sleep mode? How's the interrupt latency? Did it used to block other > >>> interrupts, or could they be stepping on each other? > >> This is done all the time. First time I used the PCON features on a > >> 88C51 was in the early 90's. You have to make sure it does a controlled > >> wake up (socks, shoes, brush teeth, etc.) and know the time it takes. > >> When you build analog/RF stuff where there needs to be radio silence > >> you've got no other choice. > > > > And IIRC, the recent iterations of 8051 variants have improved the sleep etc > > function. It used to be almost useless. > > It was not useless. I sucessfully used it in the early 90's and that one > is still in production. Same code as the old code. Yeah, but back then is was DRAM, now it's static. You can rely on variables still being there. Plus I think they introduced a 'snooze' mode. Graham
From: Eeyore on 6 Sep 2008 12:46
legg wrote: > Eeyore wrote: > >MooseFET wrote: > > > >> Is it written in ASM or C? > > > >I think he said it was all written in asssembler <yuk>. > > Can't think of a more apt instance where assembler shows it's > advantages over more bloated forms - in troubleshooting IC abnormal > behavior at a specific stage of operation. Where did I say I had any time for C ? Graham |