CPU::Emulator::6502::Op::JSR - Jump and save the return address

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

Index

Code Index:

NAME

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CPU::Emulator::6502::Op::JSR - Jump and save the return address

SYNOPSIS

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DESCRIPTION

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METHODS

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jsr( $addr )

Save return address and jump to $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::JSR;

use strict;
use warnings;

use constant INSTRUCTIONS => {
    0x20 => {
        addressing => 'absolute',
        cycles     => 6,
        code => \&jsr,
    }
};


sub jsr {
    my $self = shift;
    my $addr = shift;
    my $reg = $self->registers;
    my $mem = $self->memory;

    $reg->{ pc }--;
    $self->push_stack( $self->hi_byte( $reg->{ pc } ) );
    $self->push_stack( $self->lo_byte( $reg->{ pc } ) );
    $reg->{ pc } = $addr;
}


1;