89C51ED2
in [Design]
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From: Joerg on 6 Sep 2008 15:30 Eeyore wrote: > > 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 > ? > Comes in plastic TO92 and then it's 3-4c. > 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. > Wasn't it the BSS83 that comes in n-channel as well as p-channel? Oops! -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Joerg on 6 Sep 2008 15:31 Eeyore wrote: > > 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. > That one is static, always was. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Rich Grise on 6 Sep 2008 15:42 On Sat, 06 Sep 2008 11:18:56 +0100, TT_Man wrote: .... >> obtuse in any language; just look at the Obfuscated C Contest! > > AMEN to nice source code :) AMEN to proper COMMENTS!! Cheers! Rich
From: TT_Man on 6 Sep 2008 18:29 "MooseFET" <kensmith(a)rahul.net> wrote in message news:b23dfb00-4f2a-4273-a4c0-7d4c7e2e13a5(a)n33g2000pri.googlegroups.com... > On Sep 6, 6:15 pm, "TT_Man" <Some...(a)ntlworld.com> wrote: >> >> >> 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. >> >> > I think you need to look very carefully at the interrupt code to make >> > sure that it doesn't forget to save part of the context. This sounds >> > like it is either timing related or an uninitialized flag. >> >> No. The code runs perfectly in old date code devices and has been in >> production world wide for 15 odd years in one form or another. > > As I pointed out elsewhere, the memory locations in a given chip tend > to go to one value on power up. On a different chip they will go to a > different value. If you forgot to initialize something, this will > make some devices work and others fail. > > The timing related problem will only show if you have external inputs > other than the clock and reset pins. The true false boundary varies > from chip to chip and run to run. > > All inputs are flagged and re checked 25 ms later, If true , a flag change is set....
From: TT_Man on 6 Sep 2008 18:31
"Eeyore" <rabbitsfriendsandrelations(a)hotmail.com> wrote in message news:48C29EF2.E9632E1F(a)hotmail.com... > > > TT_Man wrote: > >> >> > I can't even begin to imagine coding some of the fairly complex (for >> >> > microcontrollers) >> >> > stuff that we did with 8051s in asm. The mind boggles. Never mind >> >> > code >> >> > maintenance. >> >> >> >> I do it all the time. It takes less time to write the code than to >> >> design it. Any competent engineer can maintain it. >> > >> > I'll send you some code shall I ? >> > >> > ASM is for twits, the clueless, poor and morons mainly AFAICS. >> > >> > I don't mind checking the asm output of PL/M to see how it's done it >> > though. Never been unsatisfied. >> >> Try writing a USB front end in C or any other HLL and see if you can get >> it >> to work........ :) > > Never been tempted by C. Doubt it would be a prob in PL/M. > > Graham > > Best achieved in totally optimised AVR assembler using all tricks known, there is one op code cycle left to stay within USNB timing constraints.. U sure you could do it in PLM? |