89C51ED2
in [Design]
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From: krw on 12 Sep 2008 07:35 In article <48C5F151.67347D1C(a)hotmail.com>, rabbitsfriendsandrelations(a)hotmail.com says... > > > krw wrote: > > > rabbitsfriendsandrelations(a)hotmail.com says... > > > 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. > > > > I used the sleep function on the 87FC51 in the late '80s without too > > much trouble (after finding that the databook was wrong). I only > > used it under battery power where my interrupt latency wasn't a > > problem (it only had to do intrusion alarm and housekeeping stuff). > > > > I rather liked the 8051, though assembler was the only way to fly on > > such a weird architecture. > > Did you ever try PL/M ? Yes, but saw no point in continuing (I did quite a bit with PLM86). The macro assembler was just as powerful, and easier to fit code into the weird x51 architecture.. -- Keith
From: Eeyore on 12 Sep 2008 08:10 krw wrote: > rabbitsfriendsandrelations(a)hotmail.com says... > > krw wrote: > > > rabbitsfriendsandrelations(a)hotmail.com says... > > > > 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. > > > > > > I used the sleep function on the 87FC51 in the late '80s without too > > > much trouble (after finding that the databook was wrong). I only > > > used it under battery power where my interrupt latency wasn't a > > > problem (it only had to do intrusion alarm and housekeeping stuff). > > > > > > I rather liked the 8051, though assembler was the only way to fly on > > > such a weird architecture. > > > > Did you ever try PL/M ? > > Yes, but saw no point in continuing (I did quite a bit with PLM86). > The macro assembler was just as powerful, and easier to fit code > into the weird x51 architecture.. The only response I can offer is that PL/M51 seems a doddle to me. It was just so nice to use. It had aspects of a HLL mixed with near ASM commands. Can't beat that in my book. It's a treat IMHO. Graham
From: MooseFET on 12 Sep 2008 10:44 On Sep 11, 3:05 pm, krw <k...(a)att.bizzzzzzzzzz> wrote: [....] > > In the ASM51, you could run with no declared bank by not putting a > > USING into the code. This is handy when you want to make code that is > > bank independent. > > > My 32 bit math library is bank independent so it can be used in > > interrupts etc. > > As long as R0-7 isn't used there is no problem. You can use R0-7 if you never absolutely address them as AR0-7. Since all instructions that use the registers, use the bank selection, it works nicely. The 64 / 32 = 32,32 divide uses every register. R0 points to the 64 bit area and R1 points to the 32 bit area. The others hold counters and saved pointers etc.
From: krw on 12 Sep 2008 13:31 In article <48CA2994.E5DD04FC(a)hotmail.com>, rabbitsfriendsandrelations(a)hotmail.com says... > > > krw wrote: > > > rabbitsfriendsandrelations(a)hotmail.com says... > > > krw wrote: > > > > rabbitsfriendsandrelations(a)hotmail.com says... > > > > > krw wrote: > > > > > > rabbitsfriendsandrelations(a)hotmail.com says... > > > > > > > krw wrote: > > > > > > > > > > > > > > > There is nothing wrong with PL/M, other than there is hasn't been > > > > > > > > support for it for a quarter century. > > > > > > > > > > > > > > What would it need support for ? > > > > > > > > > > > > Bugs (the OS variety, if nothing else). I don't use orphanware on > > > > > > new projects. I don't need to add risk to projects. > > > > > > > > > > Which bugs would those be ? The product is so mature it's untrue. > > > > > > > > Try reading. I can't take the risk of bugs cropping up in > > > > unsupported software. If there are no bugs in the compiler (don't > > > > believe it) Windows will install them. > > > > > > Ir runs under DOS. > > > > ...assuming DOS still runs. You do like to take risks! > > What a silly comment. DOS is the only stable product ever to come from Microsoft. You got a USB driver for DOS? > NO risks whatever plus the compile time on a modern PC is in the blink of an > eyelid. Shame really since even with fast ATs it was time enough to go get a > coffee. > > I can remember when applications NEVER crashed. Irrelevant. That was then. -- Keith
From: krw on 12 Sep 2008 13:31
In article <48CA2B6C.7E8E3B41(a)hotmail.com>, rabbitsfriendsandrelations(a)hotmail.com says... > > > krw wrote: > > > kensmith(a)rahul.net says... > > > krw <k...(a)att.bizzzzzzzzzz> wrote: > > > > rabbitsfriendsandrelati...(a)hotmail.com says... > > > > > krw wrote: > > > > > > rabbitsfriendsandrelati...(a)hotmail.com says... > > > > > > > krw wrote: > > > > > > > > > > > > You don't do subroutines or interrupts? > > > > > > > > > > > declare procedure XYZ interrupt(1) using 1; (register bank 1) MAIN > > > > > > > defaults to register bank zero. > > > > > > > > > > > code > > > > > > > > > > > end; > > > > > > > > > > > For example. The interrupt number defines the int source. > > > > > > > > > > Return address? USING only declares the register bank, it doesn't > > > > > > set it. > > > > > > > > > Uh ? Bloody well does unless you have a different understanding of 'does' to me. > > > > > > > > Not when I was using Intel's software. USING was only a directive > > > > to get the compiler to point R0-7 to the right place. It didn't > > > > actually load the pointers selecting the bank. > > > > > > You remember wrong. USING tells the compiler what to assume is in the > > > PSW.4, PSW.3 bits. > > > > Right, it doesn't actually point R0-7 to the appropriate hardware. > > Well, I can tell you it works or hundreds of thousands of products out there would be having awful > problems. > > When developing code I use an issue number like 0.3 for beta releases. Then 1.x for production > release etc. A major revision would take it 2.0 etc. One product we launched with a version 0.9 > expecting *someone* to report a bug so we could be smug and then up it to 1.0 for production. But > no-one ever did find a bug, so for its entire lifetime this product was shipped with version 0.9 > software ! Makes me chuckle every time that does. Furthermore it even announced it on the VFD > display. > > > > > In PLM it most likely also results in a move into > > > the PSW. > > > > Not that I remember, though I didn't use PLM/51 very long. I saw no > > advantage over assembler, armed with suitable macros. > > Speed of writing code. Excellent readability, no need to track memory freed by temporary variables > resulting in superb memory usage, you name it No speed advantage at all, for a half-competent assembly programmer. -- Keith |