确定中断例程何时结束Gameboy GB仿真

因此,关于背景,我想让你们知道到目前为止我所了解的情况:

• 中断处理由几个“中断例程”组成(对于gameboy,它有Vblank、LCD stat、计时器、操纵台和串行)。

• 中断程序有优先权(与我的问题无关)。

• 必须有 开始和结束

中断例程的结束,在处理中断之前,该例程应弹出下一条指令的地址。

我想知道:

• 只有

• 它使用REI而不是ret,因为我们希望断言ime标志仍处于启用状态,因此可以继续检查是否需要提供任何其他中断,

编辑:

所以为了给我的问题提供更多的背景,我决定发布我的指令周期代码。

#include "InteruptHandler.c"
void main(){
    while(){ //No proper argument yet. for fetch-decode-execute cycle
    opcode = fetchInstruction();
    decodeandExecuteInstruction(opcode); //Lets say an instruction is executed and it enabled the IME_flag. that is IME_flag = ENABLED

    //Check if ime_flag is enabled. processInterupt if true.
    isInteruptEnabled() ? processInterupts(): 0; //This would fall true.
    }
}

在InteruptHandler.c中

processInterupts(){

    opcode;
    bitmask = 0x01;

    //Check each bit for interupt. Bitmask will go 0x00 if the value 0x80 is shifted by 1
    for(; bitmask ; bitmask = bitmask << 1){

        //CHeck if IE and IF flag for corresponding interupt is set. process interupt if set
        IE_flag & bitmask ? (IF_flag & bitmask ? determineInterupt(bitmask) : 0) : 0; 
    }
}

determineInterupt(bitmask){

    //push the next instruction address to stack pointer
    push(PC);

    //Set PC into corresponding interupt address

//code below is my problem. I stumbled upon how would I end this function and I came up to determining when an interupt routine ends. 
//I came up with the reti function. 
//But after realizing that I already set the PC somewhere above this code, I just need to discard this code and let the main function do its instruction cycling. 
//Thanks to @duskwuff for pointing that out. 
//I just added some code to end the bitmask checking when it sees 1 interupt request and is most priotiry. 
//Also thanks to @Ped7g for giving me more information about the complexity of interupt handling. I'm not yet seeing where I should implement those. There are still so many thing to implement and yet to know when this excatly can happen.
//My question has been answered nevertheless, which is to end a function code blocks that I discarded at the end :)

//process the corresponding interupt
    do{
        opcode = fetchInstruction();
        decodeandexecuteInstruction(opcode);
    }while (opcode != RETI)
}