nRF51 Peripheral Power Control

[Andrew Lovelock]

The nRF51_reference manual describes the POWER register for the RADIO. Also that when the Power is turned on the Registers are reset. Other peripherals e.g. ECB have POWER registers defined in their data structures in the header file "nRF51.h" but these are not mentioned in the reference manual.

Q1. When turning on the POWER how soon can one write to the RADIO registers?
Q2. Which peripherals like ECB have power control? Q3 Do other peripherals reset their registers when individually powered up? Q4 How soon can one write to their registers? Q5 How soon are they functional?

Thanks

[Håkon Alseth]

Hi,

All peripherals are powered by default (set in the startup file), as there was no added current draw of enabling them. Therefore this POWER-register was removed from the SDK and documentation. Enabling the peripherals and powering them up (via deprecated POWER register) are two different tasks, both timing and current wise. For instance: Starting up the radio will require you to wait for different events

Best regards Håkon

[Andrew Lovelock]

Thanks for your reply Håkon,

Just to be clear:

1. Do you mean that when peripherals such as RNG/ECB are stopped, they are using no current ?

2. The RADIO still has a POWER register in the reference manual. Should that one be deprecated? Does the RADIO draw current when it is disabled?

Regards Andrew

[Håkon Alseth]

Hi,

1. Yes, that is correct.

2. My answer was a bit unclear, sorry for this. We had a register called PERPOWER in the early stage, which did the same as NRF_RADIO->POWER does now, but for all peripherals. The NRF_RADIO-POWER bit is by default, set to '1'. The radio will not draw any current if it is not active (by active, I mean radio is in RX or TX mode).

BR Håkon