Module: Badline::InstructionSet

Includes:
Arithmetic, Bitwise, Branch, Flag, Illegal, IncDec, Stack, Transfer
Included in:
CPU
Defined in:
lib/badline/instruction_set.rb,
lib/badline/instruction_set/flag.rb,
lib/badline/instruction_set/stack.rb,
lib/badline/instruction_set/branch.rb,
lib/badline/instruction_set/bitwise.rb,
lib/badline/instruction_set/illegal.rb,
lib/badline/instruction_set/inc_dec.rb,
lib/badline/instruction_set/transfer.rb,
lib/badline/instruction_set/arithmetic.rb

Overview

www.6502.org/tutorials/6502opcodes.html www.e-tradition.net/bytes/6502/6502_instruction_set.html

Defined Under Namespace

Modules: Arithmetic, Bitwise, Branch, Flag, Illegal, IncDec, Stack, Transfer

Instance Method Summary collapse

Methods included from Transfer

#lda, #ldx, #ldy, #sta, #stx, #sty, #tax, #tay, #tsx, #txa, #txs, #tya

Methods included from Stack

#jmp, #jsr, #pha, #php, #pla, #plp, #rti, #rts

Methods included from Illegal

#alr, #anc, #ane, #arr, #dcp, #isc, #jam, #las, #lax, #lxa, #nop_nocycle, #rla, #rra, #sax, #sbx, #sha, #shx, #shy, #slo, #sre, #tas

Methods included from Flag

#clc, #cld, #cli, #clv, #sec, #sed, #sei

Methods included from IncDec

#dec, #dex, #dey, #inc, #inx, #iny

Methods included from Branch

#bcc, #bcs, #beq, #bmi, #bne, #bpl, #bvc, #bvs

Methods included from Bitwise

#and, #asl, #bit, #eor, #lsr, #ora, #rol, #ror

Methods included from Arithmetic

#adc, #cmp, #cpx, #cpy, #sbc

Instance Method Details

#brk(_addr, _value) ⇒ Object

Forces a software interrupt (break). Pushes PC+2 and status to stack, sets break flag, and jumps via IRQ vector.

Opcodes:

$00 - implied - 7 cycles



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# File 'lib/badline/instruction_set.rb', line 30

def brk(_addr, _value)
  status.break = true
  handle_interrupt(0xfffe, brk: true, pre_cycles: 1)
  status.break = false
end

#nop(_addr, _value) ⇒ Object

No operation. Does nothing but consume a clock cycle.

Opcodes:

$EA                          - implied    - 2 cycles
$04, $44, $64                - zeropage   - 3 cycles  (illegal)
$14, $34, $54, $74, $D4, $F4 - zeropage_x - 4 cycles  (illegal)
$0C                          - absolute   - 4 cycles  (illegal)
$1C, $3C, $5C, $7C, $DC, $FC - absolute_x - 4+ cycles (illegal)
$1A, $3A, $5A, $7A, $DA, $FA - implied    - 2 cycles  (illegal)



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# File 'lib/badline/instruction_set.rb', line 45

def nop(_addr, _value)
  cycle
end