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Program Counter Relative Addressing

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Program Counter Relative Addressing is supported by nine instructions on the 65c816:

  • BCC (opcode 90)
  • BCS (opcode B0)
  • BEQ (opcode F0)
  • BMI (opcode 30)
  • BNE (opcode D0)
  • BPL (opcode 10)
  • BRA (opcode 80)
  • BVC (opcode 50)
  • BVS (opcode 70)

All of which are two bytes long.

The effective address is generated by sign-extending the 8-bit operand to 16 bits and then adding it to the program counter. The program bank register remains the same.

Syntax

BRA nearlabel

Where nearlabel is in the range of -128 to 127 bytes away from the next opcode after BRA.

See Also

References