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65816.js
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added ADC immediate

This commit is contained in:
Preston Skupinski 2011-05-07 11:02:17 -04:00
parent fc15c4c495
commit 676b111870
2 changed files with 100 additions and 1 deletions
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41
cpu.js
View File

@ -79,7 +79,8 @@ function CPU_65816() {
0x98 : TYA, 0x4c : JMP_absolute,
0x6c : JMP_absolute_indirect, 0x80 : BRA,
0xf0 : BEQ, 0xd0 : BNE, 0x90 : BCC, 0xb0 : BCS,
0x50 : BVC, 0x70 : BVS, 0x10 : BPL, 0x30 : BMI };
0x50 : BVC, 0x70 : BVS, 0x10 : BPL, 0x30 : BMI,
0x69 : ADC_const };
}
var MMU = {
@ -119,6 +120,44 @@ var MMU = {
}
};
var ADC_const = {
bytes_required:function(cpu) {
if(cpu.p.m) {
return 2;
} else {
return 3;
}
},
execute:function(cpu, bytes) {
// TODO: Signed overflow checking.
if(cpu.p.m) {
cpu.r.a += bytes[0] + cpu.p.c;
if(cpu.r.a & 0x100) {
cpu.p.c = 1;
} else {
cpu.p.c = 0;
}
cpu.r.a &= 0xff;
cpu.p.n = cpu.r.a >> 7;
} else {
cpu.r.a += (bytes[1]<<8)|bytes[0] + cpu.p.c;
if(cpu.r.a & 0x10000) {
cpu.p.c = 1;
} else {
cpu.p.c = 0;
}
cpu.r.a &= 0xffff;
cpu.p.n = cpu.r.a >> 15;
}
if(cpu.r.a===0) {
cpu.p.z = 1;
} else {
cpu.p.z = 0;
}
}
};
var BMI = {
bytes_required:function() {
return 2;

60
test/tests.js
View File

@ -18,6 +18,66 @@ function run_tests() {
test_rep();
test_sep();
test_branching();
test_adc();
}
function test_adc() {
module("ADC");
// TODO: signed overflow testing.
test("Test normal addition of two 16-bit numbers that don't cause an "+
"overflow (m bit is 0)", function() {
var cpu = new CPU_65816();
cpu.execute("18fb18c230a90100690100");
equals(cpu.r.a, 2, "0x0001 + 0x0001 should result in 0x0002 when using "+
"ADC");
equals(cpu.p.n, 0, "0x0001 + 0x0001 does not result in a negative "+
"two's complement number when adding with ADC.");
equals(cpu.p.c, 0, "0x0001 + 0x0001 should not set the carry(c) bit when "+
"adding with ADC");
equals(cpu.p.z, 0, "0x0001 + 0x0001 should not set the zero(z) bit when "+
"adding with ADC");
});
test("Test normal addition of two 8-bit numbers that don't cause an "+
"overflow (m bit is 1)", function() {
var cpu = new CPU_65816();
cpu.execute("18fb18e230a9016901");
equals(cpu.r.a, 2, "0x01 + 0x01 should result in 0x02 when using "+
"ADC");
equals(cpu.p.n, 0, "0x01 + 0x01 does not result in a negative "+
"two's complement number when adding with ADC.");
equals(cpu.p.c, 0, "0x01 + 0x01 should not set the carry(c) bit when "+
"adding with ADC");
equals(cpu.p.z, 0, "0x01 + 0x01 should not set the zero(z) bit when "+
"adding with ADC");
});
test("Test that overflow sets the carry flag and works in general with two"+
"16-bit numbers (m bit is 0)", function() {
var cpu = new CPU_65816();
cpu.execute("18fb18c230a9ffff690100");
equals(cpu.p.c, 1, "0xffff + 0x0001 should set the carry bit when using "+
"ADC");
equals(cpu.r.a, 0, "0xffff + 0x0001 should result in the accumulator "+
"being 0 when using ADC");
equals(cpu.p.n, 0, "0xffff + 0x0001 should not set the negative(n) bit "+
"when using ADC");
equals(cpu.p.z, 1, "0xffff + 0x0001 should set the zero(z) bit when using "+
"ADC");
});
test("Test that overflow sets the carry flag and works in general with two"+
"8-bit numbers (m bit is 1)", function() {
var cpu = new CPU_65816();
cpu.execute("18fb18e230a9ff6901");
equals(cpu.p.c, 1, "0xff + 0x01 should set the carry bit when using "+
"ADC");
equals(cpu.r.a, 0, "0xff + 0x01 should result in the accumulator "+
"being 0 when using ADC");
equals(cpu.p.n, 0, "0xff + 0x01 should not set the negative(n) bit when "+
"using ADC");
equals(cpu.p.z, 1, "0xff + 0x01 should set the zero(z) bit when using "+
"ADC");
});
}
function test_branching() {