LPCXpresso IDEのトピックlpc1769 - timer match register

lpc1769 - timer match register

lpcware — Wed, 15 Jun 2016 22:23:56 GMT

Content originally posted in LPCWare by inspire on Sun Jan 13 05:11:24 MST 2013
Hi,

in the LPCXpresso examples for the timer the MR0 register is set to the value where the timer interrupt occurs:

#define TIME_INTERVALmS    1000
...
LPC_TIM0->MR0 = TIME_INTERVALmS * 10; /* Set up 10 mS interval */

But now I wonder if this is absolutely right this way? When the interrupt occurs the TC value is reset. So TC moves between 0 and TIME_INTERVALmS * 10 = 10000. But this means that 10000+1 ticks have to pass until the interrupt occurs, right? So shouldn't MR0 be (TIME_INTERVALmS * 10) - 1?

Have a nice sunday!

inspire

Re: lpc1769 - timer match register

lpcware — Wed, 15 Jun 2016 22:23:57 GMT

Content originally posted in LPCWare by gbm on Sun Jan 13 05:23:43 MST 2013
You are right of course - to get N ticks you should load N-1 to MR.

Re: lpc1769 - timer match register

lpcware — Wed, 15 Jun 2016 22:23:57 GMT

Content originally posted in LPCWare by inspire on Sun Jan 13 05:31:52 MST 2013
okay thanks! :)