Noway2 wrote:> First thing is to make absolutely sure that you understand how SPI > works - get a specification. SPI consits of a master and a slave,_Is_ there "a" specification for SPI? It seems to be considerably fuzzier than, say, I2C. I could not find "a" SPI spec when I was writing my last book. I could find only general information from Motorola^H^H^H^H^H^H^H^H^HFreescale.
SPI interface -- newbie --plz help
Started by ●October 4, 2006
Reply by ●October 6, 20062006-10-06
Reply by ●October 6, 20062006-10-06
larwe wrote:> Noway2 wrote: > >>First thing is to make absolutely sure that you understand how SPI >>works - get a specification. SPI consits of a master and a slave, > > _Is_ there "a" specification for SPI? It seems to be considerably > fuzzier than, say, I2C. I could not find "a" SPI spec when I was > writing my last book. I could find only general information from > Motorola^H^H^H^H^H^H^H^H^HFreescale. >Who is Freescale? My old Motorola M68HC11 Reference Manual (M68HC11RM/AD REV 3 from 1991) has a whole chapter describing the SPI, and the QSMRM/AM (Queued Serial Module, 1991) too. Both are different (QSM has some more features), and both are totally different from TI's SPI solution which has to different shift registers for reading and writing. They (TI) shouldn't have called their silly MSP430 endpoint interface a SPI... :-( No, there is no common SPI spec at all. Bodo
Reply by ●October 6, 20062006-10-06
larwe wrote:> Noway2 wrote: > >> First thing is to make absolutely sure that you understand how SPI >> works - get a specification. SPI consits of a master and a slave, > > _Is_ there "a" specification for SPI? It seems to be considerably > fuzzier than, say, I2C. I could not find "a" SPI spec when I was > writing my last book. I could find only general information from > Motorola^H^H^H^H^H^H^H^H^HFreescale.Well, you know what you are doing, yet you managed to emit 3 copies of the above. What did you do (if anything). Maybe this is a chance to tie down the cause of duplicated messages via google. -- Some informative links: <news:news.announce.newusers <http://www.geocities.com/nnqweb/> <http://www.catb.org/~esr/faqs/smart-questions.html> <http://www.caliburn.nl/topposting.html> <http://www.netmeister.org/news/learn2quote.html> <http://cfaj.freeshell.org/google/>
Reply by ●October 6, 20062006-10-06
"larwe" <zwsdotcom@gmail.com> wrote in message news:1160139946.789151.133320@b28g2000cwb.googlegroups.com...> > Noway2 wrote: > >> First thing is to make absolutely sure that you understand how SPI >> works - get a specification. SPI consits of a master and a slave, > > _Is_ there "a" specification for SPI? It seems to be considerably > fuzzier than, say, I2C. I could not find "a" SPI spec when I was > writing my last book. I could find only general information from > Motorola^H^H^H^H^H^H^H^H^HFreescale. >There may not be an "official" spec but there is lots of good info on the net Try google for SPI +serial http://www.embedded.com/story/OEG20020124S0116 http://www.mct.net/faq/spi.html Scott
Reply by ●October 7, 20062006-10-07
In article <ua2iv3-9i4.ln1@ibrro.de>, rzany@ibrro.de says...> larwe wrote: > > Noway2 wrote: > > > >>First thing is to make absolutely sure that you understand how SPI > >>works - get a specification. SPI consits of a master and a slave, > > > > _Is_ there "a" specification for SPI? It seems to be considerably > > fuzzier than, say, I2C. I could not find "a" SPI spec when I was > > writing my last book. I could find only general information from > > Motorola^H^H^H^H^H^H^H^H^HFreescale. > > > > Who is Freescale? My old Motorola M68HC11 Reference Manual > (M68HC11RM/AD REV 3 from 1991) has a whole chapter describing > the SPI, and the QSMRM/AM (Queued Serial Module, 1991) too. > Both are different (QSM has some more features), and both are > totally different from TI's SPI solution which has to different > shift registers for reading and writing. They (TI) shouldn't > have called their silly MSP430 endpoint interface a SPI... :-( > > No, there is no common SPI spec at all.Freescale is the semiconductor division of Motorola that was spun off as a separate entity ~3 years ago. There may be differences in IMPLEMENTATION of SPI by a particular vendor; the SPECIFICATION covers how the signals on the wire should behave, and what they mean. Many of us here have made SPI work using just bit-banged I/O ports; the advent of micros with SPI hardware just makes it easier (sometimes!). --Gene
Reply by ●October 10, 20062006-10-10
hi, i am stuck with a new but strange problem related to SPI. i have configured my philips micro LPC935 as master and i am trying to view its clock output on CRO (actually DPO).but i am getting noise signals only with some garbage frequency values that are not constant.i have tried this also with ARM based microcontroller LPC2138 but i am getting same response on that also. so its a major problem because i cannot proceed with my SPI experimentation untill i am sure with clock output. please suggest what steps i can take to overcome this or what possible errors u suspect ? thank you
Reply by ●October 10, 20062006-10-10
CBFalconer wrote:> Well, you know what you are doing, yet you managed to emit 3 copies > of the above. What did you do (if anything). Maybe this is a > chance to tie down the cause of duplicated messages via google.I think you should take a job with Google, then bring them down from the inside. Anyway: when I submitted it the first and second times, I got a "temporary error occurred, please try again" message.
Reply by ●October 10, 20062006-10-10
larwe wrote:> CBFalconer wrote: > > > Well, you know what you are doing, yet you managed to emit 3 copies > > of the above. What did you do (if anything). Maybe this is a > > chance to tie down the cause of duplicated messages via google. > > I think you should take a job with Google, then bring them down from > the inside. > > Anyway: when I submitted it the first and second times, I got a > "temporary error occurred, please try again" message.sorry i didnt get you is it by someway related to my SPI problem that i posted ????
Reply by ●October 10, 20062006-10-10
abhay wrote:> larwe wrote: >> CBFalconer wrote: >> >>> Well, you know what you are doing, yet you managed to emit 3 copies >>> of the above. What did you do (if anything). Maybe this is a >>> chance to tie down the cause of duplicated messages via google. >> >> I think you should take a job with Google, then bring them down from >> the inside. >> >> Anyway: when I submitted it the first and second times, I got a >> "temporary error occurred, please try again" message. > > sorry i didnt get you > is it by someway related to my SPI problem that i posted ????No, it has nothing to do with your problem, but solely with googles habit of inciting multiple postings of the same article. Googles interface to usenet is an execresence. Avoid it if possible. Larwe is a knowledgeable user, yet still got trapped into generating the useless copies. -- "The mere formulation of a problem is far more often essential than its solution, which may be merely a matter of mathematical or experimental skill. To raise new questions, new possibilities, to regard old problems from a new angle requires creative imagination and and marks real advances in science." -- Albert Einstein