accurate timing
Posted: Mon Jul 07, 2014 7:11 pm
>from the help line
>I have used one of your 50mhz chips several years ago and found it to be a very nice platform for personal projects. that chip has served me well and i\'m looking to upgrade to the arm7 60mhz board.
>My new project requires that I have a very precise timer. As such, what kind of timing could I expect to get out of the arm7 60mhz? Would there be a reason to go with the 50mhz boards instead? If I could get down to 5 or 10 nanoseconds accurately that should work. I did not see this info on the website, but it doesn\'t mean its not available.
The most accurate timing you can get from a 60 MHz CPU is 1/60 MHz or 16 nsec, and that would require reprogramming the PCLK setup for the TIMER hardware as it normally is running at 1/4 that rate to save power.
In addition most of our boards are using the internal RC oscillator which is trimmed at the factory to be 1% accurate. All our current boards allow a crystal to be added for better accuracy, typical crystals are 0.01 % accurate.
We will be introducing an LPC4330 based board in the next month or so that will have a crystal installed and will be running at 200 MHz, which would give you 5 nsec timing accuracy when using the TIMER hardware.
>I have used one of your 50mhz chips several years ago and found it to be a very nice platform for personal projects. that chip has served me well and i\'m looking to upgrade to the arm7 60mhz board.
>My new project requires that I have a very precise timer. As such, what kind of timing could I expect to get out of the arm7 60mhz? Would there be a reason to go with the 50mhz boards instead? If I could get down to 5 or 10 nanoseconds accurately that should work. I did not see this info on the website, but it doesn\'t mean its not available.
The most accurate timing you can get from a 60 MHz CPU is 1/60 MHz or 16 nsec, and that would require reprogramming the PCLK setup for the TIMER hardware as it normally is running at 1/4 that rate to save power.
In addition most of our boards are using the internal RC oscillator which is trimmed at the factory to be 1% accurate. All our current boards allow a crystal to be added for better accuracy, typical crystals are 0.01 % accurate.
We will be introducing an LPC4330 based board in the next month or so that will have a crystal installed and will be running at 200 MHz, which would give you 5 nsec timing accuracy when using the TIMER hardware.