Hi, Will, Thanks a lot for your reply.
Yes，the hardwear processor clock frequency of nRF52 (Cortex M4F) is 64 MHz and can not be changed. The reason of changing CLOCK_FREQ is that I want re-use the internal timing of mynewt already there with more accurate timing, by calling function "os_cputime_get32()”. I’m trying to implement a (soft) IC card reader by nRF52 with mynewt OS and nimble stack running. I am also considering to use an independent timer (NRF_TIMER3 or NRF_TIMER4) at the cost of about 0.1mA current. I already use NRF_TIMER2 to provide a 4 MHz clock signal output from GPIO of nRF52. By reading the source code of apache-mynewt-core, my understanding is that NRF_TIMER0 and NRF_TIMER1 is already used by mynewt OS and nimble stack, is my understanding correct? Thanks, Jiacheng > 在 2017年1月9日，01:10，will sanfilippo <[email protected]> 写道： > > Those should be the only two parameters you need to configure. Must be a bug > in the controller :-) > > I think it is worthwhile to point out that CLOCK_FREQ only changes the units > of os cputime; it does not affect the speed at which the processor runs. At > least, I could not see any other uses of CLOCK_FREQ. So, these settings only > affect the nimble stack and the controller specifically (internal controller > timing). > > I am curious why you wanted to change this variable; what were you trying to > achieve? > > Thanks for pointing this out; I will take a look to see why it is not working. > >> On Jan 7, 2017, at 10:48 PM, WangJiacheng <[email protected]> wrote: >> >> Hi, >> >> The default CPU time frequency of Mynewt OS and Nimble stack is 1 MHz, I try >> to change the CPU time frequency to be 2 MHz, I modified the related 2 >> config files: >> configure file “hw/bsp/nrf52dk/syscfg.yml” as >> CLOCK_FREQ: >> description: 'TBD' >> value: 2000000 >> configure file “kernel/os/syscfg.yml” as >> OS_CPUTIME_FREQ: >> description: 'Frequency of os cputime' >> value: 2000000 >> >> The app “bleperiph" is running and the CPU time frequency is 2 MHz, also the >> BLE “nimble-bleprph” peripheral can be scanned by LightBlue of iOS APP, and >> show 1 service is there. However, when I try to connect it ,an error massage >> “Connection Alert: Timeout interrogating the peripheral” >> >> When change back above 2 syscfg parameters to 1000000, it can be connected. >> >> And app “bletiny” is the same. >> >> Is there any missed config setting in my test? How to change the CPU time >> frequency to 2 Mhz and Nimble device can be connected? >> >> Thanks, >> >> Jiacheng >> >> >
