Forums

8051

Started by zibidi February 1, 2006
In article <drrhtt$d0k$1@slavica.ukpost.com>, Ian Bell
<ruffrecords@yahoo.com> writes
>Pete Fenelon wrote: > >> The 8051 is a target that most RTOS vendors avoid, with good reason. >> Hell, we've ported an RTOS to the PIC18, but even we weren't mad enough >> to consider the 8051. I certainly wouldn't do it for fun. >> > >I would have thought the PIC18 would have even worse than the 8051. >
It depends which 8051... -- \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ \/\/\/\/\ Chris Hills Staffs England /\/\/\/\/ /\/\/ chris@phaedsys.org www.phaedsys.org \/\/\ \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
Chris Hills wrote:

> In article <drrhtt$d0k$1@slavica.ukpost.com>, Ian Bell > <ruffrecords@yahoo.com> writes >>Pete Fenelon wrote: >> >>> The 8051 is a target that most RTOS vendors avoid, with good reason. >>> Hell, we've ported an RTOS to the PIC18, but even we weren't mad enough >>> to consider the 8051. I certainly wouldn't do it for fun. >>> >> >>I would have thought the PIC18 would have even worse than the 8051. >> > > It depends which 8051... >
The problem for a pre-emptive OS is stack. No 8051 variant has a stack greater then 256 bytes (and in practice it is rather less). Some OS get round this by using XRAM to save non running processes' stacks but this is slow. Most (all?) PICs have a fixed, inaccessible and rather small stack which makes it harder to write an RTOS IMHO. Ian
> >> > >>I would have thought the PIC18 would have even worse than the 8051. > >> > The problem for a pre-emptive OS is stack. No 8051 variant has a stack > greater then 256 bytes (and in practice it is rather less). Some OS get > round this by using XRAM to save non running processes' stacks but this is > slow. > > Most (all?) PICs have a fixed, inaccessible and rather small stack which > makes it harder to write an RTOS IMHO. > > Ian
The other problem is the lack of data pointers on the 8051. The pic18 have 3 I think so you can easily make your own data stack and plenty on onboard ram to accomodate it.
In article <drt2ms$nm0$1@slavica.ukpost.com>, Ian Bell
<ruffrecords@yahoo.com> writes
>Chris Hills wrote: > >> In article <drrhtt$d0k$1@slavica.ukpost.com>, Ian Bell >> <ruffrecords@yahoo.com> writes >>>Pete Fenelon wrote: >>> >>>> The 8051 is a target that most RTOS vendors avoid, with good reason. >>>> Hell, we've ported an RTOS to the PIC18, but even we weren't mad enough >>>> to consider the 8051. I certainly wouldn't do it for fun. >>>> >>> >>>I would have thought the PIC18 would have even worse than the 8051. >>> >> >> It depends which 8051... >> > >The problem for a pre-emptive OS is stack. No 8051 variant has a stack >greater then 256 bytes (and in practice it is rather less). Some OS get >round this by using XRAM to save non running processes' stacks but this is >slow.
Technically the 8052 family.... the 8051 did not have the upper 128 IData space. though I don't know of any of the 51 familty that don't have it now
>Most (all?) PICs have a fixed, inaccessible and rather small stack which >makes it harder to write an RTOS IMHO. >
I once got asked if I could supply a full TCP/IP stack for a PIC!! -- \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ \/\/\/\/\ Chris Hills Staffs England /\/\/\/\/ /\/\/ chris@phaedsys.org www.phaedsys.org \/\/\ \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
"Pete Fenelon" <pete@fenelon.com> wrote in message 
news:q50rrd.eo3.ln@fenelon.com...
> zibidi <onurakdemir1@gmail.com> wrote: >> HI all, >> I am trying to implement a 8051 based RTOS. > > The 8051 is a target that most RTOS vendors avoid, with good reason. > Hell, we've ported an RTOS to the PIC18, but even we weren't mad enough > to consider the 8051. I certainly wouldn't do it for fun.
The 8051 is far friendly than PIC18. The 8051 has a real stack in RAM that can be far larger than the PIC18. The PIC18 has a fixed stack size of eight while the 8051 could easily have a stack size of 128 bytes. Thats a big deal for an RTOS. The 8051 has no banking to deal with either. Why do PICs STILL bank. The 8051 replaced the 8048 that had banking. A renovation that happened in 1985.
<cbarn24050@aol.com> wrote in message 
news:1138889081.215022.10890@g47g2000cwa.googlegroups.com...
> >> >> >> >>I would have thought the PIC18 would have even worse than the 8051. >> >> >> The problem for a pre-emptive OS is stack. No 8051 variant has a stack >> greater then 256 bytes (and in practice it is rather less). Some OS get >> round this by using XRAM to save non running processes' stacks but this >> is >> slow. >> >> Most (all?) PICs have a fixed, inaccessible and rather small stack which >> makes it harder to write an RTOS IMHO. >> >> Ian > > The other problem is the lack of data pointers on the 8051. The pic18 > have 3 I think so you can easily make your own data stack and plenty on > onboard ram to accomodate it.
8051 -> DPTR
On 2006-02-02, kobus <jacobuses@spoornet.co.za> wrote:

> I've designed and used a minimal RTOS for the last 15 years I call it > RTE51 (Real Time Executive). Because of the way that it is used, it is > fairly immune to latch ups. It can execute up to 8 task preemptively
"fairly immune to latch ups?" That doesn't sound good. I would only use an RTOS that _never_ "latches up". -- Grant Edwards grante Yow! Someone is DROOLING at on my collar!! visi.com
Meindert Sprang wrote:
> "tesla" <yusufilker@gmail.com> wrote in message > news:1138872167.887306.287990@z14g2000cwz.googlegroups.com... > > zibidi wrote: > > yes I want it , it can be useful for me. I decide to implement a > > Round robin schedular with only 8 task as well. Also I think I am goint > > to use C , so I cant use register bank 0 also 1 as I see.(functions use > > them) > > zibidi > > > zibidicigim neden 8051 kullaniyorsun. > (Silicon labs in 100 mhz lik 8051 leri hari=E7) > Yok illa RTOS yazacam diyorsan bisey demem de > ama ARM kullansan freeRTOS ida port etmisler bak ne hos.. > Zati C de yazacakmissin.. oh kebab yaa > > Couldn't have said it better myself... ?!?!? > > Meindert
Hi Meindert, I just tried to convince him to use ARM with freeRTOS. But it seems you know Turkish a little bit. or you see "kebab" and guessed it is Turkish...
"tesla" <yusufilker@gmail.com> wrote in message
news:1138898621.085906.299820@z14g2000cwz.googlegroups.com...
> Hi Meindert, > I just tried to convince him to use ARM with freeRTOS. > But it seems you know Turkish a little bit. > or you see "kebab" and guessed it is Turkish...
Wel, to be honest, I didn't understand one single word of it. I didn't even notice the word kebab... :-) In the Netherlands there are a lot of people who are form Turkey or have their roots there and therefore we see Turkish subtitles on television quite regularly. So I could have guessed it was Turkish... Meindert
Ian Bell <ruffrecords@yahoo.com> wrote:

> The problem for a pre-emptive OS is stack. No 8051 variant has a stack > greater then 256 bytes (and in practice it is rather less).
BZZZZ! --- and thanks for playing ;-) Check out the DS80C390: 1 kB of dedicated stack space. And it's even in on-chip XDATA memory so it doesn't even eat up valuable IDATA. -- Hans-Bernhard Broeker (broeker@physik.rwth-aachen.de) Even if all the snow were burnt, ashes would remain.