SNES Interrupt Handling. More...

#include <snes/types.h>

Typedefs
typedef void(*	VBlankCallback) (void)
	VBlank callback function pointer type.

Functions
void	nmiClear (void)
	Clear the VBlank callback.

void	nmiSet (VBlankCallback callback)
	Register a VBlank callback function.

void	nmiSetBank (VBlankCallback callback, u8 bank)
	Register a VBlank callback with explicit bank.

Detailed Description

SNES Interrupt Handling.

Manages NMI (VBlank), IRQ, and other interrupts.

Author: OpenSNES Team

Copyright: MIT License

Typedef Documentation

◆ VBlankCallback

typedef void(* VBlankCallback) (void)

VBlank callback function pointer type.

Functions of this type can be registered with nmiSet() to be called automatically during every VBlank interrupt.

Function Documentation

◆ nmiClear()

void nmiClear ( void )

Clear the VBlank callback.

Equivalent to nmiSet(NULL).

◆ nmiSet()

void nmiSet ( VBlankCallback callback )

Register a VBlank callback function.

The registered callback will be called during every VBlank interrupt, BEFORE the vblank_flag is set. This allows time-critical operations (like DMA transfers) to be performed reliably during VBlank.

Parameters

callback Function to call during VBlank, or NULL to disable

void myVBlankHandler(void) {
    // DMA transfer, scroll updates, etc.
}
 
int main(void) {
    consoleInit();
    nmiSet(myVBlankHandler);
    while (1) {
        WaitForVBlank();
        // Game logic here
    }
}

Note: Keep callbacks short! VBlank time is limited (~2200 CPU cycles on NTSC); Callback runs with interrupts disabled; The callback function must be in the same ROM bank as the main code (bank 0). For larger projects, use nmiSetBank() to specify the bank explicitly.

◆ nmiSetBank()

void nmiSetBank	(	VBlankCallback	callback,
		u8	bank
	)

Register a VBlank callback with explicit bank.

Use this when the callback function might not be in bank 0.