89C51ED2
in [Design]
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From: TT_Man on 7 Sep 2008 11:56 "Eeyore" <rabbitsfriendsandrelations(a)hotmail.com> wrote in message news:48C37379.9A6A2C47(a)hotmail.com... > > > mpm wrote: > >> A wider clock register on 8051's would be nice > > Please please please ! It's one of the few sillies in them. Just 24 bits > would be nice > > Graham > And what's wrong with doing them under interrupts?????
From: TT_Man on 7 Sep 2008 11:59 > > Some of the more recent ones including I suspect the ED2 have more IP > bits. > > Intel were smart to leave open those possibilities. > > Graham > Most current flavour'51s' have more interrupts than I would know what to do with. AVRs have even more, but that's another book.....
From: TT_Man on 7 Sep 2008 12:03 >> > Hmmm that's not how to code 8051 inrterrupts. >> >> Huh?????? >> >> Do you mean that you don't save the interrupted context???? !!!!! > > I can't remember my reason for saying that now. Flags perhaps ? > > Anyway PL/M handles all that for one. Declare procedure interrupt ! > > Graham > Coding in assembler opens all sorts of clever trick possibilities that HLL guys would never have dreamed of. That only comes with years of developing RT asm code. Why push a couple of status bytes when they can be saved in half the time by moving them to registers in the current bank.......... Doesn't work for everyone though......
From: TT_Man on 7 Sep 2008 12:05 "MooseFET" <kensmith(a)rahul.net> wrote in message news:80fdab35-9c4f-4537-9237-d23ef03b79e1(a)v39g2000pro.googlegroups.com... > On Sep 7, 6:29 am, "TT_Man" <Some...(a)ntlworld.com> wrote: >> "MooseFET" <kensm...(a)rahul.net> wrote in message >> > [....] >> >> > 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.... > > It could be a narrow window of timing that is causing the problem. > Try changing the clock speed just a a little and see if the problem > goes away. > > Why should I? The problem lies in the manufacture of the chip, not my code. In any case, if it's missed by 1 nanosecond, it will catch it next time round, unless you can pull and release a trigger within 100 microseconds...
From: TT_Man on 7 Sep 2008 12:07
>> >Me too........ >> >> Funny, this week I spent two days porting 5000 lines of C from an 8051 >> to >> a 16bit PIC. The PIC is vastly superior to an 89C51ED2 in almost every >> respect including being less than half the price. >> >> If back in 1994 when I started on the first version of those 5000 lines I >> had chosen to write in assembler I would be feeling a bit of a clueless >> twit this week and probably for another month or two. > > I see no way anyone can write complex asm as fast as coding in an HLL. > > What's the cost of 'time to market' and lost sales when it makes the > difference between being say the first out with the new widget and 3rd or > 4th > ? > > Graham > The difference is our product is a world leader and no one comes even near.So far. |