does nrf51822 support the function of cortex-m0?i cant see any document about this
does nrf51822 support the function of cortex-m0?i cant see any document about this
Hi,
The nRF51x22 series is based on a M0 core, and will support all required functions of a M0 core. However, there are some (optional) features that are taken out. The SYSTICK is replaced with a more configurable RTC0/1 peripheral for instance.
All M0 generic information is found at ARMs site: www.arm.com/.../cortex-m0.php
Best regards Håkon
I agree, we only see a fraction of the application that this device is applicable for. We try to add the peripherals that developers need and what applications that our devices are being used in, and sometime this can cause a tradeoff in terms of the number of peripherals that are included into one series. We are very open to feedback on what should be done in a different way, or what's missing from our devices to be able to provide an improved product.
One thing to note about the systick is: The systick is very limited, as it's only able to set it in a limited range (1 ms / 10 ms?) and it is not very stable in terms of frequency tolerance (usually sources by RC oscillator, meaning tolerance of percents). What we have added instead is a low-power RTC module (RTC0/RTC1) which can be sourced by a external 32 kHz, synthesized 32kHz from 16 MHz clock, or by a 32 kHz RC oscillator (can be calibrated to 250 ppm) Since we offer a bluetooth low energy stack, we have to comply with the bluetooth SIGs requirements towards timing, tolerance, and resolution of the 32 kHz source. This could not be achieved with a SYSTICK, which is the main reason why we took it out and added RTC0/RTC1.
Regarding the timers, its true that one of these is blocked by the softdevice, but it leaves 2 timers open for the application. Each of these timers have 4 capture/compare registers which can be used freely by the application. Are you running out of timers in your application?
I will report your comments and feedback back to our management.
Best regards Håkon
I agree, we only see a fraction of the application that this device is applicable for. We try to add the peripherals that developers need and what applications that our devices are being used in, and sometime this can cause a tradeoff in terms of the number of peripherals that are included into one series. We are very open to feedback on what should be done in a different way, or what's missing from our devices to be able to provide an improved product.
One thing to note about the systick is: The systick is very limited, as it's only able to set it in a limited range (1 ms / 10 ms?) and it is not very stable in terms of frequency tolerance (usually sources by RC oscillator, meaning tolerance of percents). What we have added instead is a low-power RTC module (RTC0/RTC1) which can be sourced by a external 32 kHz, synthesized 32kHz from 16 MHz clock, or by a 32 kHz RC oscillator (can be calibrated to 250 ppm) Since we offer a bluetooth low energy stack, we have to comply with the bluetooth SIGs requirements towards timing, tolerance, and resolution of the 32 kHz source. This could not be achieved with a SYSTICK, which is the main reason why we took it out and added RTC0/RTC1.
Regarding the timers, its true that one of these is blocked by the softdevice, but it leaves 2 timers open for the application. Each of these timers have 4 capture/compare registers which can be used freely by the application. Are you running out of timers in your application?
I will report your comments and feedback back to our management.
Best regards Håkon