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Message

Re: RTC manipulation (ctd.)

2004-12-27 by lp2000c

I have not tried it.

--- In lpc2000@yahoogroups.com, Leighton Rowe <leightonsrowe@y...> 
wrote:
> Have u experienced this problem too? I decided to rest the matter 
since nobody else could reproduce the problem or find the bug in my 
code (if any).
> 
> lp2000c <lp2000c@e...> wrote:
> 
> Did you ever resolve this issue, or confirm that there is a bug?
> 
> --- In lpc2000@yahoogroups.com, "Leighton Rowe" 
<leightonsrowe@y...> 
> wrote:
> > 
> > Yep,
> > 
> > PLLSTAT says that the PLL's enabled, connected & locked.
> > 
> > I'm running the code on a mcb2100 as well (12MHz crystal). I made 
a 
> > mistake about the processor on the mcb2100 though...it's actually 
a 
> > 2124 that replaced the original 2129 (it got toasted :-/). 
> > My other board is the 2114 with a 14.7456MHz xtal.
> > 
> > So, I'd imagine the code will work ok on all 2129's, as you've 
> > shown. There might be an issue with 2114/24's I'm using. I'm 
trying 
> > to verify that with Philips...or anyone here that has them.
> > 
> > best regards,
> > Leighton
> > 
> > --- In lpc2000@yahoogroups.com, "Pete" <peterbrown_abroad@y...> 
> > wrote:
> > > 
> > > 
> > > Hi Leighton,
> > > 
> > > Im using the MCB2100 development board from Keil for the time 
> > being. 
> > > Our main control unit is in development as we speak...
> > > 
> > > anyway, the MCB is stuffed with the LPC2129, crystal of 12Mhz.
> > > 
> > > I have tested my system using YOUR CODE that you pasted below, 
> and 
> > I 
> > > agree with my previous answers...the clock WORKS OK at all 
VPBDiv 
> > > settings....
> > > 
> > > i print the time to terminal (38400baud) and monitor the time 
for 
> > > several minutes and it certainly does not run fast (or fast 
> enough 
> > > to visually see anyway!)...
> > > 
> > > so i am very confused why you see this problem....
> > > 
> > > so i guess i cannot help any further.... but hope the above 
helps 
> > a 
> > > little....
> > > 
> > > daft question - are u sure that your PLL is enabled and running?
> > > 
> > > let me know if you find the solution,
> > > rgds
> > > pete
> > > 
> > > 
> > > 
> > > --- In lpc2000@yahoogroups.com, "Leighton Rowe" 
> > <leightonsrowe@y...> 
> > > wrote:
> > > > 
> > > > Thanks for your results
> > > > 
> > > > What lpc are you using by the way? Is your RTC counting at 
the 
> > > right 
> > > > speed when VPBDIV=0? Try comparing the RTC timers against a 
> > normal 
> > > > clock if u can.
> > > > 
> > > > I tried your code on my 12 MHz board (M=5), and this is what 
I 
> > get.
> > > > VPBDIV = 0 so VPB = 15MHz (cclk/4)
> > > > PREINT = 0x000001c8;
> > > > PREFRAC = 0x000061c0;
> > > > RTC runs OK, but it's going twice as fast.
> > > > ....
> > > > VPBDIV = 1 then  VPB = 60MHz (cclk)
> > > > PREINT = 0x00000726;
> > > > PREFRAC = 0x00000700;
> > > > RTC runs OK. Speed is normal.
> > > > ....
> > > > VPBDIV = 2 then  VPB = 30MHz (cclk/2)
> > > > PREINT = 0x00000392;
> > > > PREFRAC = 0x00004380;
> > > > RTC runs OK. Speed is normal.
> > > > 
> > > > For now, It's still unsolved over here.
> > > > 
> > > > Thanks,
> > > > Leighton
> > > > 
> > > > I've included pieces of my code just for reference.
> > > > ************************************
> > > > #define XTAL_FREQ     12000000
> > > > //#define XTAL_FREQ     14745600
> > > > #define MULTIPLIER    5
> > > > //#define MULTIPLIER    4
> > > > #define CCLK          (XTAL_FREQ * MULTIPLIER)      // system 
> > > clock 
> > > > system clock (cclk)
> > > > #define PCLK          (CCLK / 2)
> > > > //#define PCLK          CCLK
> > > > //#define PCLK          (CCLK / 4)
> > > > 
> > > > if(PCLK == CCLK)
> > > > { 
> > > >   VPBDIV = 1;
> > > > }
> > > > else if(PCLK == CCLK/2)
> > > > { 
> > > >   VPBDIV = 2;
> > > > }
> > > > else if(PCLK == CCLK/4)
> > > > { 
> > > >   VPBDIV = 0;
> > > > }
> > > > 
> > > > CCR = AMR = CIIR = ILR = 0;   //clear all RTC Misc registers
> > > > SEC = MIN = HOUR = 0;       //clear timer registers being used
> > > > 
> > > > //Setup Prescalar Values
> > > > PREINT = (PCLK/32768) - 1;               //integer value
> > > > PREFRAC =PCLK - ((PREINT + 1)* 32768);   //fraction value
> > > > 
> > > > CCR |= 2;                         //reset timer
> > > > CCR &= ~2;
> > > > CCR |= 1;                        //start timer
> > > > 
> > > > 
> > > > 
> > > > 
> > > > --- In lpc2000@yahoogroups.com, "Pete" 
<peterbrown_abroad@y...> 
> > > > wrote:
> > > > > 
> > > > > 
> > > > > ok, got home and have tried on my dev board...
> > > > > Using a 12Mhz crystal, I configured the VPBDiv=0
> > > > > 
> > > > > As a result modified the Fac and Int settings to:
> > > > > PREINT             = 0x000001c8;//Set RTC prescaler for 
> > > > 12.000Mhz Xtal,
> > > > >       VBP=15Mhz
> > > > > PREFRAC       = 0x000061c0;
> > > > > 
> > > > > using the calculations from databook.
> > > > > 
> > > > > I also then had to change my UART settings to match, sicne 
> the 
> > > > PCLK 
> > > > > was now 1/4.....
> > > > > Anyway: ALL WORKS OK. RTC functions normally.
> > > > > 
> > > > > Can you check what values you used for the Prefac/int when 
> you 
> > > > > adjusted the VPBDiv?
> > > > > 
> > > > > Or, since you have it working maybe issue is closed?
> > > > > 
> > > > > anyway, thought i would report my findings!
> > > > > 
> > > > > rgds
> > > > > pete
> > > > > 
> > > > > 
> > > > > So I am confused that you say you had problem with the 
> > > > > 
> > > > > --- In lpc2000@yahoogroups.com, "bty639886" 
> <peter.brown@b...> 
> > > > wrote:
> > > > > > 
> > > > > > when i get home i will check this out on my systsem.
> > > > > > 
> > > > > > I do however have a 12Mhz clock rather than the 14.xx 
that 
> u 
> > > are 
> > > > > > using. So my preints and facs will be different.
> > > > > > Im suspecting the problem could well be with your prefac 
> > being 
> > > 0 
> > > > > > given the divider settings...
> > > > > > 
> > > > > > anyway, i will check it out and re-post for future 
> reference.
> > > > > > 
> > > > > > glad you got it working !
> > > > > > rgds
> > > > > > pete
> > > > > > 
> > > > > > 
> > > > > > --- In lpc2000@yahoogroups.com, "Leighton Rowe" 
> > > > > <leightonsrowe@y...> 
> > > > > > wrote:
> > > > > > > 
> > > > > > > > 3. have you tried running with vpbdiv set to 1 (ie 
> > > resulting 
> > > > > in 
> > > > > > > > 60mhz opertion (ish).. i am using that for my system 
> > > without 
> > > > > any 
> > > > > > > > problem...
> > > > > > > 
> > > > > > > Good news!
> > > > > > > 
> > > > > > > After setting VPBDIV = 1 (pclk =cclk) and setting 
PREINT 
> > and 
> > > > > > PREFRAC 
> > > > > > > (based on the user manual), the RTC counted correctly. 
> > > Thanks 
> > > > > > Pete. 
> > > > > > > The RTC also worked for VPBDIV = 2 (pclk = cclk/2).
> > > > > > > 
> > > > > > > But interestingly, the RTC still counted twice as fast 
> > after 
> > > > > using 
> > > > > > > VPBDIV = 0. I repeated everything on 2 different lpcs 
> > > (lpc2114 
> > > > > > > @14.7456MHz & lpc2129 @12MHz). You can even try it out 
on 
> > > your 
> > > > > > own; 
> > > > > > > I wouldn't be surprised you'll get the same results. 
and 
> > got 
> > > > the 
> > > > > > > same results. 
> > > > > > > 
> > > > > > > So RTC's OK only when vpbdiv = 1 (pclk=cclk) or 2 (pclk 
= 
> > > > > cclk/2). 
> > > > > > > Otherwise RTC's doubles in speed when vpbdiv = 0 
> (cclk/4). 
> > I 
> > > > > hope 
> > > > > > > Philips has an explanation for this one...I have no 
clue 
> > > why. 
> > > > > > > 
> > > > > > > For now, I can live with using a different vpbdiv 
setting 
> > to 
> > > > > make 
> > > > > > > everything work. 
> > > > > > > 
> > > > > > > Thanks again
> 
> 
> 
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