oldoldman

I'm using nestang_nano20k.gprj on the master branch. And the IDE is EDU. BTW, I've tried nestang-0.7.2rc , which works fine.

I've found from [here](https://github.com/Blimp01/pico_non_blocking_timer/blob/master/non_blocking_timer.c#L16) that if I "override" the isr_systick in [crt0.s](https://github.com/raspberrypi/pico-sdk/blob/master/src/rp2_common/pico_crt0/crt0.S#L47), the SysTick will work. So I guess the irq number of SysTick is SIO_IRQ_PROC0. Is there any doc...

But this is from the ARMv6-M arch doc So SysTick is an interrupt. But it is not that important. And I must admit that what I guess is wrong. The...

In my understanding of the ARM doc, SysTick is a kind of interrupt and interrupt is a kind of exception. So they are used interchangably.