AnsweredAssumed Answered

reading Timer Status Reg kills timer?

Question asked by larsen.james on Jun 9, 2011
Latest reply on Jun 12, 2011 by larsen.james
We are using the Atollic IDE.  After setting up TIM2,TIM3, or TIM4 to clock continuously.  We output the counter bits on PCx lines and monitor with a scope.

We read the registers directly using:
adr=0x40000???;
data=*((u16 *)(adr)); and then write the data to the PCx lines.

We can read all regs. with no problems except for the counter status regs at 0x40000?10.  If we read the status reg the counter stops.  This is for all status registers and any counter.  For example: if we read 0x40000810, the TIM4_SR, TIM2 will stop.  This seems really odd.  I might accept the fact that somehow reading TIM2_SR might mess with TIM2 but do not understand how it could mess with TIM4, etc.  We are trying to monitor the UIF and TIF flags.

Does anybody have any suggestions?  

Outcomes