XOSC_STATUS_FREQ_RANGE reads as 1, contradicting datasheet

[Ferdi265]

Summary

The XOSC_STATUS_FREQ_RANGE bits (bits 0 and 1) in the XOSC_STATUS register are documented to "always read 0". However, on real hardware (RP2040 on a Raspberry Pi Pico), the result reads as 1.

Expected Behaviour

RP2040 documentation (page 246) and SDK documentation (hardware/regs/xosc.h:90) both state that XOSC_STATUS_FREQ_RANGE "always reads 0".

The table of legal values is:

//               0x0 -> 1_15MHZ
//               0x1 -> RESERVED_1
//               0x2 -> RESERVED_2
//               0x3 -> RESERVED_3

Actual Behaviour

XOSC_STATUS_FREQ_RANGE reads as 1.

Other

If you need any further information from me, such as the RP2040 chip id and hardware revision, please state so and I will gladly provide them.