CPU::Emulator::6502::Op::LDA - Load accumulator from memory

Games-NES-Emulator documentation Contained in the Games-NES-Emulator distribution.

Index

Code Index:

NAME

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CPU::Emulator::6502::Op::LDA - Load accumulator from memory

SYNOPSIS

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DESCRIPTION

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METHODS

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lda( $addr )

Loads the accumulator from $addr.

AUTHOR

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Brian Cassidy <bricas@cpan.org>

COPYRIGHT AND LICENSE

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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

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* CPU::Emulator::6502
Games-NES-Emulator documentation Contained in the Games-NES-Emulator distribution. 
package CPU::Emulator::6502::Op::LDA;

use strict;
use warnings;

use constant INSTRUCTIONS => {
    0xA9 => {
        addressing => 'immediate',
        cycles => 2,
        code => \&lda,
    },
    0xA5 => {
        addressing => 'zero_page',
        cycles => 3,
        code => \&lda,
    },
    0xB5 => {
        addressing => 'zero_page_x',
        cycles => 4,
        code => \&lda,
    },
    0xAD => {
        addressing => 'absolute',
        cycles => 4,
        code => \&lda,
    },
    0xBD => {
        addressing => 'absolute_x',
        cycles => 4,
        code => \&lda,
    },
    0xB9 => {
        addressing => 'absolute_y',
        cycles => 4,
        code => \&lda,
    },
    0xA1 => {
        addressing => 'indirect_x',
        cycles => 6,
        code => \&lda,
    },
    0xB1 => {
        addressing => 'indirect_y',
        cycles => 5,
        code => \&lda,
    },
};


sub lda {
    my $self = shift;
    my $reg = $self->registers;
    $reg->{ acc } = $self->RAM_read( shift ) & 0xff;
    $self->set_nz( $reg->{ acc } );
}


1;