Post by thread:[PIC]: The 16C54 and RTCC

(This might should have been OT -- it is sometimes hard to know exactly where the dividing line might be). Suddenly having a need for a C compiler, and having downloaded the PICCLITE compiler (for which I am eternally grateful to Hi-Tech, for having made it available at no charge to students and hobbyists, seeing as I consider myself to be in both camps) I find a strange thing, and hope someone can clear it up for me. There are some sample programs, and one called METRO.C (a metronome program - surprise!!) seems to be one I can adapt for my metronome project. According to the comments, it is written for a 16C54 chip. OK. I can deal with that, thought I. I want to use a 16F628 chip, so obviously have to see what differences there are. Not many, or at least none that will prevent it from being used. HOWEVER -- the program would not compile because there is an undeclared variable, by the name of RTCC. It appears to me that RTCC and TMR0 are the same, and so this is not a big thing. Except that I am curious as to why they called it RTCC. Is this a historical thing? Did TMR0 used to be called RTCC? The data sheet for the 16C54 makes no mention of RTCC. (I just know that someone is going to write me and tell me that I only have to change it to TMR0. Hey, I know that already!! :-) I just wonder why it was called RTCC.) John -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

HOWEVER -- the program would not compile because there is an undeclared variable, by the name of RTCC. It appears to me that RTCC and TMR0 are the same, and so this is not a big thing. Except that I am curious as to why they called it RTCC. Is this a historical thing? Did TMR0 used to be called RTCC? The data sheet for the 16C54 makes no mention of RTCC. Yes, it's historical. My 1992 databook mentions only RTCC and no TMR0. Now I'm sorta wishing I'd saved my 1984 databook as well, although it looks like not much happened between 84 and 92. I guess they didn't change the names till they introduced a PIC with more than one timer... BillW -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

John Nall <spam_OUTPICLISTTakeThisOuTmitvma.mit.edu> wrote: > the program would not compile because there is an undeclared > variable, by the name of RTCC. It appears to me that RTCC and > TMR0 are the same, and so this is not a big thing. Except that I > am curious as to why they called it RTCC. Is this a historical > thing? Did TMR0 used to be called RTCC? The data sheet for the > 16C54 makes no mention of RTCC. You are correct; RTCC (Real Time Clock/Counter) is what Microchip used to call TMR0. -Andy === Andrew Warren -- .....aiwKILLspam@spam@cypress.com === Principal Design Engineer === Cypress Semiconductor Corporation === === Opinions expressed above do not === necessarily represent those of === Cypress Semiconductor Corporation -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

At 07:27 PM 4/9/03 -0400, John Nall wrote: >HOWEVER -- the program would not compile because there is an undeclared >variable, by the name of RTCC. It appears to me that RTCC and TMR0 are the >same, and so this is not a big thing. Except that I am curious as to why >they called it RTCC. Is this a historical thing? Did TMR0 used to be >called RTCC? The data sheet for the 16C54 makes no mention of RTCC. Yep - PICs used to have only 1 timer called RTCC (Real Time Clock Counter). Then they started to grow up into the PICs we know today. Another change that occured along the way: INADR is now called INDF. There are undoubtedly others. dwayne -- Dwayne Reid <dwaynerKILLspamplanet.eon.net> Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 19 years of Engineering Innovation (1984 - 2003) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

>HOWEVER -- the program would not compile because >there is an undeclared variable, by the name of >RTCC. It appears to me that RTCC and TMR0 are >the same, and so this is not a big thing. In the PICC Lite include directory is a file called pic1684.h, which has these two lines in it: static volatile unsigned char RTCC @ 0x01; static volatile unsigned char TMR0 @ 0x01; If you were using the 16F84/A your code would have compiled. I guess they figured the 16F628 is "new" so why bother dragging the old constant around. __________________________________________________ Do you Yahoo!? Yahoo! Tax Center - File online, calculators, forms, and more http://tax.yahoo.com -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Dwayne Reid <.....PICLISTKILLspam.....mitvma.mit.edu> wrote: > Another change that occured along the way: INADR is now called > INDF. Dwayne: Do you have an old Microchip datasheet that refers to that register as INADR? I don't remember that register even HAVING a name until they decided to call it INDF; in my early 16C54 code, I just called it USEFSR. > There are undoubtedly others. They had at least one bit whose original "official" name began with a numeric digit... I forget exactly which, but it could easily have been the one that put the UART into 9-bit mode; "9BIT" is an excellent name for that bit until you actually need to write code that accesses it. Offhand, I can't think of any others. -Andy === Andrew Warren -- EraseMEaiwspam_OUTTakeThisOuTcypress.com === Principal Design Engineer === Cypress Semiconductor Corporation === === Opinions expressed above do not === necessarily represent those of === Cypress Semiconductor Corporation -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

> > You are correct; RTCC (Real Time Clock/Counter) is what > Microchip used to call TMR0. > > -Andy > In modern usage, doesn't "real-time clock" mean something that either keeps "clock time" or a large count of seconds (with fractions) that can be converted to clock time? I am thinking of the DS1994 real-time clock iButton and similar devices. Alex -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listservspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body

At 08:11 AM 4/10/03 -0500, Alex Kilpatrick wrote: > > > > You are correct; RTCC (Real Time Clock/Counter) is what > > Microchip used to call TMR0. > >In modern usage, doesn't "real-time clock" mean something that either >keeps "clock time" or a large count of seconds (with fractions) that can >be converted to clock time? I am thinking of the DS1994 real-time clock >iButton and similar devices. Perhaps. But Microchip's usage of that term was accurate - by using that timer, one could write code that kept track of real time accurate to within 1 clock cycle over a period of years. Have a look at the app note that describes Microchip's version of a clock radio controller (alarm clock) for some of the techinques used. This would have been much more difficult without that timer. dwayne -- Dwayne Reid <@spam@dwaynerKILLspamplanet.eon.net> Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 19 years of Engineering Innovation (1984 - 2003) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email KILLspamlistservKILLspammitvma.mit.edu with SET PICList DIGEST in the body