---
title: "Interrupts"
canonical_url: https://developer.repebble.com/pebbleos/docs/kernel/interrupts/
last_updated: 2026-10-21
sdk_version: 4.33.1
---
# Interrupts

Source: https://developer.repebble.com/pebbleos/docs/kernel/interrupts/

SoC interrupts are bound at build time; there is no runtime handler registration and the vector table is in flash:

```
PBL\_IRQ\_CONNECT(I2C1, 5, pbl\_i2c\_sf32lb\_irq\_handler, &s\_i2c1, 0);PBL\_IRQ\_DIRECT(AON, 0, PBL\_IRQ\_ZERO\_LATENCY) {/\* handler body \*/}
```

A line is named after its `PBL_SOC_IRQN_<line>` define in the SoC’s checked-in `soc_irqs.h`, which also gives its number: `PBL_IRQN(I2C1)` is `PBL_SOC_IRQN_I2C1`. Binding a line needs no vendor header. The SoC’s line count is `CONFIG_NUM_IRQS` and its priority bits `CONFIG_NUM_IRQ_PRIO_BITS`, both set in `soc/*/Kconfig.defconfig`.

`PBL_IRQ_CONNECT()` calls `isr(arg)` with whatever type `isr` takes (an empty `arg` calls `isr()`); `PBL_IRQ_DIRECT()` takes the handler body instead. Binding a line twice fails to link, and a line without a `PBL_SOC_IRQN_<line>` fails to compile.

The priority is in controller units (0 is the most urgent) and is programmed for every connected line by `pbl_irq_init()` at boot, so drivers only call `pbl_irq_enable()` and `pbl_irq_disable()`. A priority more urgent than `PBL_IRQ_PRIO_MAX_SYSCALL` is a build error unless the line is flagged `PBL_IRQ_ZERO_LATENCY`, in which case the ISR must not call the kernel. An enabled line nobody connected lands in `arch_irq_spurious()`, which asserts.

Generated from PebbleOS [3a7b71785](https://github.com/coredevices/pebbleos/commit/3a7b71785fd439666c4a8bc116f561140e8dec01). This page is maintained in the pebbleos repository: [docs/kernel/interrupts.md](https://github.com/coredevices/pebbleos/blob/3a7b71785fd439666c4a8bc116f561140e8dec01/docs/kernel/interrupts.md).