> Van: Olin Lathrop > Aan: PICLIST@MITVMA.MIT.EDU > Onderwerp: Re: [PIC]: 16C74a - I2C module & vague documentation. - Didanyone receive this message ? > Datum: maandag 14 augustus 2000 14:54 > > > As in the subject. Did anyone recieve the below message ? I can't > believe > > no-one knows anything about the SSP/I2C-Module of the 16C74A .... > > Yes, I remember seeing this message earlier. People don't reply for various > reasons. I didn't because you were asking very detailed questions that I > couldn't have answered without some time reading the data sheet again. You > asked so many questions that it seemed to me the problem was a general > confusion about IIC instead of a problem with specific PIC issues, and I saw > no point duplicating the well written introduction to IIC in the Microchip > literature. As I remember, none of the questions where pointed at the I2C -protocol in general, but at how he different states are remembered/handled within the controller. Especially how the Status-bits (of the controller) respond. > > > I'm trying to write some code for the 16C74A's I2C-module, and have > > > a nice time interpreting the documentation. I've got MicroChip's > > > Microcontroller databook in front of me (1996/1997 edition, document > > > DS30390D) , and have some questions about the following: > > I didn't notice this before, but that is probably an old book. Either > get the most recent data sheet, or look on the Microchip web site. Well, you where right. I've got a CD here, the "First Edition 2000" that holds a new document (DS30390e). I just checked it, but it only adds specs for the ' 76 & ' 77. Nothing has changed for the orthers. :-( > IIC is relatively complex, and you definitely have to do some reading, > especially the first time you try to use it. I do remember the Microchip > documentation to be quite good, even providing background on how IIC works > in general. There may also be an app note or two. Check the web site. I think I've got a working knowledge of how the I2C-bus works, and I can bit-bang it in MasterMode on (for example) a 16x84. I've even written (machine-language) routines so I can access I2C-devices off a PC's Printer-port (interface-hardware limited to a few diodes & resistors). > Keep in mind that many of the PICs don't have the support to do master > mode in hardware. I believe the 16C74A falls into this category. I gave > up on the IIC module and controlled the lines directly from the firmware > in master mode. Fortunately master mode is the easy one because you > control the clock. I am implementing the Slave-mode. Regards, Rudy Wieser -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics