When the SAMD21 Arduino core enables external oscillator (XOSC32K), it sets a start-up time of around 2 secs with the instruction SYSCTRL_XOSC32K_STARTUP( 0x6u ), (startup.c, line 353). The timings are described on data sheet page 185.
This guarantees a stable clock, however, it hangs the chip during startup quite a while - too bad for quick starting and power saving applications.
On the SAMD51 there is no such wait. Why not removing it for the SAMD21 too?
When the SAMD21 Arduino core enables external oscillator (XOSC32K), it sets a start-up time of around 2 secs with the instruction
SYSCTRL_XOSC32K_STARTUP( 0x6u ), (startup.c, line 353). The timings are described on data sheet page 185.This guarantees a stable clock, however, it hangs the chip during startup quite a while - too bad for quick starting and power saving applications.
On the SAMD51 there is no such wait. Why not removing it for the SAMD21 too?