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added controller input

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This commit is contained in:
Lauchmelder 2021-10-30 21:01:27 +02:00
parent 640df2feb2
commit 674ee5059b
6 changed files with 83 additions and 5 deletions
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2
NES Emulator/CMakeLists.txt
View file

@ -1,6 +1,6 @@
cmake_minimum_required (VERSION 3.8)
add_executable (nesemu "main.c" "bus.c" "cpu.c" "cartridge.c" "opcodes.c" "log.c" "ppu.c" "mappers/mapper000.c" "mapper.c")
add_executable (nesemu "main.c" "bus.c" "cpu.c" "cartridge.c" "opcodes.c" "log.c" "ppu.c" "mappers/mapper000.c" "mapper.c" "controller.c")
target_include_directories(nesemu PUBLIC ${SDL2_INCLUDE_DIRS})
target_link_libraries(nesemu PUBLIC ${SDL2_LIBRARIES})

16
NES Emulator/bus.c
View file

@ -74,7 +74,12 @@ Byte readBus(struct Bus* bus, Word addr)
}
else if (0x4000 <= addr && addr <= 0x4017) // I/O space
{
val = bus->io[addr - 0x4000];
switch (addr)
{
case 0x4016:
val = pollInput(&bus->controller);
break;
}
}
else if (0x4020 <= addr && addr <= 0xFFFF) // Cartridge space
{
@ -102,7 +107,14 @@ void writeBus(struct Bus* bus, Word addr, Byte val)
}
else if (0x4000 <= addr && addr <= 0x4017) // I/O space
{
bus->io[addr - 0x4000] = val;
switch (addr)
{
case 0x4016:
bus->controller.strobe = (val & 0x1);
if (val & 0x1)
fillRegister(&bus->controller);
break;
}
}
else if (0x4020 <= addr && addr <= 0xFFFF) // Cartridge space
{

4
NES Emulator/bus.h
View file

@ -2,12 +2,15 @@
#define _BUS_H_
#include "types.h"
#include "controller.h"
#include <SDL.h>
struct CPU;
struct PPU;
struct Cartridge;
// Main communication path for devices and memory in the NES
struct Bus
{
@ -17,6 +20,7 @@ struct Bus
struct CPU* cpu;
struct PPU* ppu;
struct Cartridge* cartridge;
struct Controller controller;
Byte masterClockTimer;

30
NES Emulator/controller.c Normal file
View file

@ -0,0 +1,30 @@
#include "controller.h"
#include <SDL.h>
Byte pollInput(struct Controller* controller)
{
if (controller->strobe)
{
fillRegister(controller);
}
Byte ret = 0x1 - (controller->latch & 0x1); // Controller port is active low
controller->latch >>= 1;
return ret;
}
void fillRegister(struct Controller* controller)
{
Byte* keyboard = SDL_GetKeyboardState(NULL);
controller->data.A = keyboard[SDL_SCANCODE_A];
controller->data.B = keyboard[SDL_SCANCODE_S];
controller->data.Up = keyboard[SDL_SCANCODE_UP];
controller->data.Down = keyboard[SDL_SCANCODE_DOWN];
controller->data.Left = keyboard[SDL_SCANCODE_LEFT];
controller->data.Right = keyboard[SDL_SCANCODE_RIGHT];
controller->data.Select = keyboard[SDL_SCANCODE_LSHIFT];
controller->data.Start = keyboard[SDL_SCANCODE_RETURN];
controller->latch = controller->data.raw;
}

32
NES Emulator/controller.h Normal file
View file

@ -0,0 +1,32 @@
#ifndef _CONTROLLER_H_
#define _CONTROLLER_H_
#include "types.h"
struct Controller
{
union
{
struct
{
Byte A : 1;
Byte B : 1;
Byte Select : 1;
Byte Start : 1;
Byte Up : 1;
Byte Down : 1;
Byte Left : 1;
Byte Right : 1;
};
Byte raw;
} data;
Byte strobe;
Byte latch;
};
Byte pollInput(struct Controller* controller);
void fillRegister(struct Controller* controller);
#endif // _CONTROLLER_H_

4
NES Emulator/cpu.c
View file

@ -68,7 +68,7 @@ int tickCPU(struct CPU* cpu)
cpu->nmi = 0;
printf("NMI TRIGGERED FROM $%04x\n", cpu->pc.word);
// printf("NMI TRIGGERED FROM $%04x\n", cpu->pc.word);
cpu->pc.lo = readBus(cpu->bus, 0xFFFA);
cpu->pc.hi = readBus(cpu->bus, 0xFFFB);
@ -225,7 +225,7 @@ void prepareFetch(struct CPU* cpu)
void fetch(struct CPU* cpu)
{
if(cpu->currentOpcode->addr != IMP)
if(cpu->currentOpcode->addr != IMP && cpu->currentOpcode->addr != ACC)
cpu->fetchedVal = readBus(cpu->bus, cpu->fetchedAddress);
}