89C51ED2
in [Design]
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From: MooseFET on 5 Sep 2008 12:08 On Sep 5, 1:46 pm, Robert Baer <robertb...(a)localnet.com> wrote: > TT_Man wrote: > > "Eeyore" <rabbitsfriendsandrelati...(a)hotmail.com> wrote in message > >news:48BF4043.AE375BE5(a)hotmail.com... > > >>TT_Man wrote: > > >>>Anyone using this part experiencing problems? we have used them for 4 > >>>years > >>>or so. Date codes up to 0705 work ok, 0814 misbehaves....same chip, same > >>>software, 0814 doesn't execute properly... > > >>Have you contacted the manufacturer ? > > >>Graham > > > Yes, that was my first port of call, with full details, source code etc.and > > an indication of the approximate area of failure, within 10 lines of > > code...... > > *Within* 10 lines of code? Not more specific? Probably "C" code... I think two causes are most likely: (1) Something isn't being initialized. The memory locations of an 8051 are not forced reset at power on. They can have any value in them but a given chip will tend to either have highs or lows. (2) A timing of interrupt issue. If the interrupt code messes with something that the non-interrupt code uses, the results can depend on the exact timing of interrupts. Which instruction an interrupt happens on can be effected by where the chip's 0/1 boundary is on the input lines.
From: TT_Man on 5 Sep 2008 12:53 ">> >> >> 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. >> >> >> Graham >> >> 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.
From: Eeyore on 5 Sep 2008 13:23 Spehro Pefhany wrote: > Eeyore wrote: > >Rich Grise wrote: > > > >> If I could get an 8051 equivalent but with Motorola's timer system (see > >> 68HC11, e.g.), I'd be in hog heaven. ;-) > > > >What's so great about Motorola's timers ? > > Much better designed. In any specific way ? The only thing I might like in 8051 family timers is more than 16 bits. Graham
From: Eeyore on 5 Sep 2008 13:30 MooseFET wrote: > Eeyore wrote: > > MooseFET wrote: > > > > > Is it written in ASM or C? > > > > 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. I still use PL/M 51. So easy to use. You can treat it as highish level language and set a register directly in the next line. 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. Graham
From: Eeyore on 5 Sep 2008 13:34
MooseFET wrote: > "TT_Man" <Some...(a)ntlworld.com> wrote: > > >> > Does the code have interrupts enabled? > > > > >> > Is it written in ASM or C? > > > > >> 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. > > > > >> Graham > > > > Not a prayer in hell 100% assembler. :) > > Are you using interrupts? in PLM/51 Declare procedure blah-blah interrupt(n) using (n); code end; |