CPU::Emulator::6502::Op::DEY - Decrement the Y register

Games-NES-Emulator documentation

Contained in the Games-NES-Emulator distribution.

Index

NAME
SYNOPSIS
DESCRIPTION
METHODS
- dey( )
AUTHOR
COPYRIGHT AND LICENSE
SEE ALSO
- * CPU::Emulator::6502

Code Index:

package CPU::Emulator::6502::Op::DEY
- dey
EOF

NAME

CPU::Emulator::6502::Op::DEY - Decrement the Y register

SYNOPSIS

DESCRIPTION

METHODS

dey( )

Decrements the Y register by 1.

AUTHOR

Brian Cassidy <bricas@cpan.org>

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.

SEE ALSO

* CPU::Emulator::6502

Games-NES-Emulator documentation

Contained in the Games-NES-Emulator distribution.

package CPU::Emulator::6502::Op::DEY;

use strict;
use warnings;

use constant INSTRUCTIONS => {
    0x88 => {
        cycles => 2,
        code  => \&dey,
    }
};

sub dey {
    my $self = shift;
    my $reg = $self->registers;

    $reg->{ y } = ( $reg->{ y } - 1 ) & 0xff;
    $self->set_nz( $reg->{ y } );
}

1;