and, asl, enable/disable flags

3 files changed, 77 insertions, 3 deletions

diff --git a/CPU.c b/CPU.c
index db7948c..b44a84c 100644
--- a/CPU.c
+++ b/CPU.c
@@ -129,9 +129,9 @@ uint16_t get_operand_address(struct CPU *cpu, enum adressing_mode mode){
 
 void update_zero_and_negative_flags(struct CPU *cpu, uint8_t result){
     if(result == 0)
-        cpu->status |= 0b00000010;
+        enable_flag(cpu, ZERO);//cpu->status |= 0b00000010;
     else
-        cpu->status &= 0b11111101;
+        disable_flag(cpu, ZERO);//cpu->status &= 0b11111101;
 
     if((result & 0b10000000) != 0)
         cpu->status |= 0b10000000;
@@ -154,6 +154,34 @@ void sta(struct CPU *cpu, enum adressing_mode mode){
     mem_write(cpu, addr, cpu->register_a);
 }
 
+void and(struct CPU *cpu, enum adressing_mode mode){
+    uint16_t addr = get_operand_address(cpu, mode);
+    uint8_t value = mem_read(cpu, addr);
+
+    cpu->register_a &= value;
+    update_zero_and_negative_flags(cpu, cpu->register_a);
+}
+
+void enable_flag(struct CPU *cpu, uint8_t flag){
+    cpu->status |= flag;
+}
+
+void disable_flag(struct CPU *cpu, uint8_t flag){
+    cpu->status &= !flag;
+}
+
+void asl(struct CPU *cpu, enum adressing_mode mode){
+    uint16_t addr = get_operand_address(cpu, mode);
+    uint8_t value = mem_read(cpu, addr);
+
+    if(value >> 7 == 1) enable_flag(cpu, CARRY);
+    else disable_flag(cpu, CARRY);
+
+    value = value << 1;
+    mem_write(cpu, addr, value);
+    update_zero_and_negative_flags(cpu, value);
+}
+
 void interpret(struct CPU *cpu){
 
     while(1){
@@ -179,6 +207,21 @@ void interpret(struct CPU *cpu){
                 cpu->register_x++;
                 update_zero_and_negative_flags(cpu, cpu->register_x);
                 break;
+            case AND:
+                and(cpu, OPCODE[opcode].mode);
+                cpu->pc += OPCODE[opcode].bytes - 1;
+                break;
+            case ASL:
+                if(OPCODE[opcode].mode == NoneAddressing){
+                    uint8_t value = cpu->register_a;
+                    if(value >> 7 == 1) enable_flag(cpu, CARRY);
+                    else disable_flag(cpu, CARRY);
+                    cpu->register_a = value << 1;
+                    update_zero_and_negative_flags(cpu, cpu->register_a);
+                }else{
+                    asl(cpu, OPCODE[opcode].mode);
+                }
+                cpu->pc += OPCODE[opcode].bytes - 1;
             default:
                 break;
         }
diff --git a/CPU.h b/CPU.h
index 6157914..4600621 100644
--- a/CPU.h
+++ b/CPU.h
@@ -1,6 +1,15 @@
 #ifndef _CPU
 #define _CPU
 
+#define CARRY              0b00000001
+#define ZERO               0b00000010
+#define INTERRUPT_DISABLE  0b00000100
+#define DECIMAL_MODE       0b00001000
+#define BREAK              0b00010000
+#define BREAK2             0b00100000
+#define OVERFLOW           0b01000000
+#define NEGATIV            0b10000000
+
 struct CPU{
     uint8_t register_a;
     uint8_t register_x;
@@ -37,5 +46,10 @@ void lda(struct CPU *cpu, enum adressing_mode mode);
 void interpret(struct CPU *cpu);
 uint16_t mem_read_u16(struct CPU *cpu, uint16_t pos);
 uint16_t get_operand_address(struct CPU *cpu, enum adressing_mode mode);
+void and(struct CPU *cpu, enum adressing_mode mode);
+void enable_flag(struct CPU *cpu, uint8_t flag);
+void disable_flag(struct CPU *cpu, uint8_t flag);
+void asl(struct CPU *cpu, enum adressing_mode mode);
+
 
 #endif
\ No newline at end of file
diff --git a/opcode_pc.h b/opcode_pc.h
index 8a95db8..7a79bbe 100644
--- a/opcode_pc.h
+++ b/opcode_pc.h
@@ -9,12 +9,14 @@ enum _INSTRUCTION{
     BRK,
     STA,
     INX,
+    AND,
+    ASL,
 };
 
 struct _OPCODE{
     enum _INSTRUCTION instruction; 
     enum adressing_mode mode;
-    int bytes;
+    uint8_t bytes;
 }OPCODE[0xFF];
 
 void init_opcode_pc(){
@@ -41,6 +43,21 @@ void init_opcode_pc(){
     OPCODE[0x91] = (struct _OPCODE){STA, Indirect_Y, 2};
     /*INX*/   
     OPCODE[0xE8] = (struct _OPCODE){INX, NoneAddressing, 1}; 
+    /*AND*/
+    OPCODE[0x29] = (struct _OPCODE){AND, Immediate, 2};
+    OPCODE[0x25] = (struct _OPCODE){AND, ZeroPage, 2};
+    OPCODE[0x35] = (struct _OPCODE){AND, ZeroPage_X, 2};
+    OPCODE[0x2D] = (struct _OPCODE){AND, Absolute, 3};
+    OPCODE[0x3D] = (struct _OPCODE){AND, Absolute_X, 3};
+    OPCODE[0x39] = (struct _OPCODE){AND, Absolute_Y, 3};
+    OPCODE[0x21] = (struct _OPCODE){AND, Indirect_X, 2};
+    OPCODE[0x31] = (struct _OPCODE){AND, Indirect_Y, 2};    
+    /*ASL*/
+    OPCODE[0x0A] = (struct _OPCODE){ASL, NoneAddressing, 1};
+    OPCODE[0x06] = (struct _OPCODE){ASL, ZeroPage, 2};
+    OPCODE[0x16] = (struct _OPCODE){ASL, ZeroPage_X, 2};
+    OPCODE[0x0E] = (struct _OPCODE){ASL, Absolute, 3};
+    OPCODE[0x1E] = (struct _OPCODE){ASL, Absolute_X, 3};    
 }
 
 #endif
\ No newline at end of file