6502
/
65816.js
mirror of https://github.com/pskupinski/65816.js.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

added basic memory mapped i/o support

This commit is contained in:
Preston Skupinski 2011-05-30 17:23:00 -04:00
parent 688c2aaaa3
commit 150d6e57d2
2 changed files with 48 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
TODO
View File

@ -37,7 +37,7 @@ Memory:
- Page wrapping or not wrapping for certain addressing modes and with certain
settings
- ROM protection
- Memory mapped I/O
- Improve the memory mapped I/O interface and handling
Display:
- Using the html page included provide a nice interface for using the cpu
emulator and provide many features helpful for debugging

58
cpu.js
View File

@ -227,9 +227,9 @@ function CPU_65816() {
}
this.mmu.push_byte(this.r.pc>>8);
this.mmu.push_byte(this.r.pc&0xff);
var p_byte = (cpu.p.n<<7)|(cpu.p.v<<6)|(cpu.p.m<<5)|(cpu.p.x<<4)|
(cpu.p.d<<3)|(cpu.p.i<<2)|(cpu.p.z<<1)|cpu.p.c;
cpu.mmu.push_byte(p_byte);
var p_byte = (this.p.n<<7)|(this.p.v<<6)|(this.p.m<<5)|(this.p.x<<4)|
(this.p.d<<3)|(this.p.i<<2)|(this.p.z<<1)|this.p.c;
this.mmu.push_byte(p_byte);
if(!this.p.e)
this.p.d = 0;
this.p.i = 1;
@ -325,49 +325,85 @@ function CPU_65816() {
var MMU = {
cpu: {},
memory: { 0: {} },
memory_mapped_io_devices: {},
add_memory_mapped_io_device: function(write_callback, read_callback, bank,
location) {
if(typeof this.memory_mapped_io_devices[bank] === 'undefined') {
this.memory_mapped_io_devices[bank] = {};
}
this.memory_mapped_io_devices[bank][location] = { write: write_callback, read: read_callback };
},
pull_byte: function() {
if(this.cpu.p.e) {
if(this.cpu.r.s===0xff) {
this.cpu.r.s = 0;
return this.memory[this.cpu.r.dbr][0x100|this.cpu.r.s];
return this.read_byte(0x100);
} else {
return this.memory[this.cpu.r.dbr][0x100|(++this.cpu.r.s)];
return this.read_byte(0x100|(++this.cpu.r.s));
}
} else {
return this.memory[this.cpu.r.dbr][++this.cpu.r.s];
return this.read_byte(++this.cpu.r.s);
}
},
push_byte: function(b) {
if(this.cpu.p.e) {
if(this.cpu.r.s===0) {
this.memory[this.cpu.r.dbr][0x100|this.cpu.r.s] = b;
this.store_byte(0x100, b);
this.cpu.r.s = 0xff;
} else {
this.memory[this.cpu.r.dbr][0x100|(this.cpu.r.s--)] = b;
this.store_byte((0x100|(this.cpu.r.s--)), b);
}
} else {
this.memory[this.cpu.r.dbr][this.cpu.r.s--] = b;
this.store_byte(this.cpu.r.s--, b);
}
},
read_byte: function(location) {
return this.memory[this.cpu.r.dbr][location];
var device_map_at_bank = this.memory_mapped_io_devices[this.cpu.r.dbr];
if(device_map_at_bank!=null) {
var device = device_map_at_bank[location];
if(device!=null)
return device.read();
}
return this.memory[this.cpu.r.dbr][location];
},
read_byte_long: function(location, bank) {
if(typeof this.memory[bank] === 'undefined') {
this.memory[bank] = {};
}
var device_map_at_bank = this.memory_mapped_io_devices[bank];
if(device_map_at_bank!=null) {
var device = device_map_at_bank[location];
if(device!=null)
return device.read();
}
return this.memory[bank][location];
},
store_byte: function(location, b) {
this.memory[this.cpu.r.dbr][location] = b;
var device_map_at_bank = this.memory_mapped_io_devices[this.cpu.r.dbr];
if(device_map_at_bank!=null) {
var device = device_map_at_bank[location];
if(device!=null)
device.write(b);
}
this.memory[this.cpu.r.dbr][location] = b;
},
store_byte_long: function(location, bank, b) {
if(typeof this.memory[bank] === 'undefined') {
this.memory[bank] = {};
}
var device_map_at_bank = this.memory_mapped_io_devices[bank];
if(device_map_at_bank!=null) {
var device = device_map_at_bank[location];
if(device!=null)
device.write(b);
}
this.memory[bank][location] = b;
},