Errata - Datasheets W65C02S

Errors in the latest (October 19, 2010) datasheet from WDC:

p. 6, section 1.1

There are 70 instructions (which are listed in table 5-1), not 69.

p. 20, Table 4-1

  • Absolute Indexed Indirect (a,x) row:
    • NMOS 6502 Instruction Times should be - not 5
    • W65C02S Instruction Times should be 6 not 5
    • NMOS 6502 Program Sequence Bytes should be - not 3
  • Absolute Indirect (a) row:
    • NMOS 6502 Instruction Times should be 5 not 4 (3)
    • W65C02S Instruction Times: should be 6 not 4 (3)
  • Program Counter Relative r row: both Instruction Times columns should also include note 1
  • Stack s row: Program Sequence Bytes columns should be 1 (JSR is listed elsewhere as absolute, not stack addressing)
  • Zero Page Indirect Indexed with Y (zp),y row: both Instruction Times columns should include note 1
  • Clarification: note that this table is merely a (simplified) summary; footnote 1 would imply that a STA abs,X instruction would take 4 cycles when a page boundary is not crossed; however, STA abs,X takes 5 cycles (whether or not a page boundary is crossed)

p. 21, Table 5-1

PHX and PHY are new instructions, but are not noted as such

p. 22, Table 5-2

  • 00: BRK is "s" (stack) addressing mode, not "a" (absolute)
  • A2: LDX # is not an old instruction with a new addressing mode
  • 34: BIT zp,x is an old instruction with a new addressing mode
  • 86: STZ zp should be STX zp
  • 96: STZ zp,y should be STX zp,y
  • 89: BIT # is an old instruction with a new addressing mode
  • 3A: DEC A is an old instruction with a new addressing mode
  • 4A: LSR A is not an old instruction with a new addressing mode
  • 8C: STY a is not a new instruction
  • 9C: STZ a is a new instruction
  • BE: LDX a,x should be LDX a,y

p. 29, table 6-4

  • STZ zp should be 64, not 68
  • a,x is not a valid addressing mode for TAY; that entry should be empty, not BC
  • TAY i should be A8 (eight), not AB (bee)
  • TRB a should be 1C (one), not IC (eye)
  • a,x is not a valid addressing mode for TRB; that entry should be empty, not 5E

A "nice to have" omission

A cycle-by-cycle Instruction operation table for the 65C02, like table 5-7 in the (August 3, 2009) 65C816 datasheet. The February 2004 and March 6, 2000 65C02 datasheets had such a table, but that table has been omitted from the latest datasheet.

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