package CPU::Emulator::6502::Op::CPX;
use strict;
use warnings;
use constant INSTRUCTIONS => {
0xE0 => {
addressing => 'immediate',
cycles => 2,
code => \&cpx
},
0xE4 => {
addressing => 'zero_page',
cycles => 3,
code => \&cpx
},
0xEC => {
addressing => 'absolute',
cycles => 4,
code => \&cpx
}
};
=head1 NAME
CPU::Emulator::6502::Op::CPX - Compare the X register
=head1 SYNOPSIS
=head1 DESCRIPTION
=head1 METHODS
=head2 cpx( $addr )
Compares the X register to the data held at $addr.
=cut
sub cpx {
my $self = shift;
my $reg = $self->registers;
my $temp = $reg->{ x } - $self->memory->[ shift ];
$reg->{ status } &= CPU::Emulator::6502::CLEAR_SZC;
$self->set_nz( $temp );
$reg->{ status } |= CPU::Emulator::6502::SET_CARRY if $temp < 0x100;
}
=head1 AUTHOR
Brian Cassidy E<lt>bricas@cpan.orgE<gt>
=head1 COPYRIGHT AND LICENSE
Copyright 2007 by Brian Cassidy
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
=head1 SEE ALSO
=over 4
=item * L<CPU::Emulator::6502>
=back
=cut
1;