Hello all,
the way we calculate 1 machine cycle period in 8051 clock = 12MHz then 1m/c = 1/ (12MHz / 12) = 1 usec
In case of ARM7, I have peripheral clock for timer = 12Mhz (after doing all the calculations of PLL) can you guide me the time period of 1 machine cycle in case of ARM7. does it mean 1 m/c = (1/12Mhz) = 83 nsec
Please guide..
Thanks and regards.
Hello Mike, Thanks for reply. you are right. but does that mean peripheral clock cycle = 1/12MHz = 83nsec I want to generate timer clock = 5 msec I can use the formula to generate 5msec but I want to know whether one timer tick = 83nsec as peripheral clock = 12Mhz for timer. Is it right? thanks
This kind of information would be in the datasheet and/or user manual for your MCU. I can't read them for you since you did not say which MCU you are using.
Hello Mike, I am using lpc2387. and timer is running at 12Mhz. and it is not mentioned in datasheet about machine cycle. thanks
a similar example I think you are looking for can be found in the STM32F2-F4 demonstration Builder project.
It offers this and an ISR timer for the F2 device the clock is 120Mhz
void USB_OTG_BSP_uDelay (const uint32_t usec) { #ifdef USE_ACCURATE_TIME BSP_Delay(usec,TIM_USEC_DELAY); #else __IO uint32_t count = 0; const uint32_t utime = (120 * usec / 7); do { if ( ++count > utime ) { return ; } } while (1); #endif }