The upper 6 interrupts in each NVIC are not connected to hardware, but could still be used for software IRQ (for example, RTIC can use these for software tasks).
Interrupts have to live under a peripheral, so I added SW_IRQ at address 0x0 to group them under.
Since there a no fields in this peripheral it should not matter what the address is, if I understand it correctly. We could also append them to an existing peripheral if this is a concern.
This was brought up in #236
The upper 6 interrupts in each NVIC are not connected to hardware, but could still be used for software IRQ (for example, RTIC can use these for software tasks). Interrupts have to live under a peripheral, so I added SW_IRQ at address 0x0 to group them under. Since there a no fields in this peripheral it should not matter what the address is, if I understand it correctly. We could also append them to an existing peripheral if this is a concern. This was brought up in #236