diff --git a/src/sdk_compat.h b/src/sdk_compat.h
index 935dce2..cb3bc32 100644
--- a/src/sdk_compat.h
+++ b/src/sdk_compat.h
@@ -6,6 +6,16 @@ static __always_inline void pio_sm_set_jmp_pin(PIO pio, uint sm, uint jmp_pin) {
       (pio->sm[sm].execctrl & ~PIO_SM0_EXECCTRL_JMP_PIN_BITS) |
       (jmp_pin << PIO_SM0_EXECCTRL_JMP_PIN_LSB);
 }
+
+static_assert(PIO1_BASE - PIO0_BASE == (1u << 20), "hardware layout mismatch");
+#define PIO_INSTANCE(instance) ((pio_hw_t *)(PIO0_BASE + (instance) * (1u << 20)))
+static __always_inline PIO pio_get_instance(uint instance) {
+    invalid_params_if(HARDWARE_PIO, instance >= NUM_PIOS);
+    return PIO_INSTANCE(instance);
+}
+
+#define PIO_IRQ_NUM(pio, irqn) (PIO0_IRQ_0 + NUM_PIO_IRQS * PIO_NUM(pio) + (irqn))
+
 #endif
 
 #if PICO_SDK_VERSION_MAJOR < 2 || (PICO_SDK_VERSION_MAJOR == 2 && PICO_SDK_VERSION_MINOR < 1)