High frequency PWM shifts phase when radio is active

[grow mane]

When setting up a 1Mhz square wave using NRF_PWM on the NRF52 or GPIOTE on the NRF51 while BLE is advertising, the PWM stops when the radio is active. The problem doesn't happen when the frequency is below 6khz. No PWM interrupt is enabled. Is this an unavoidable limitation with high PWM frequencies?

[Stanislav Silnitskiy]

Hi! not sure, but looks like interference with softdevice (SD), which in fact doesn't like when you manage hardware by ports directly. Although, if you run your code within Timelots, looks like something unavoidable, if SD still required for operation.

[Ole Bauck]

Only certain registers are restricted or blocked by the SoftDevice and should not be accessed directly, see here.