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or

The or instructions compute a bitwise and as shown in the table below. All flags are updated accordingly. Note that the carry and overflow flags are set iff (lhs | rhs)==0xff & carry_in==1 due to jankiness of the 74382's or function mode.

InstructionEncodingSemanticsCycles
or acc, reg801 101 rrraccacc OR reg8\mathit{acc} \gets \mathit{acc}~\mathrm{OR}~\mathit{reg8}3/41/52
or acc, imm800 101 011 imm8accacc OR imm8\mathit{acc} \gets \mathit{acc}~\mathrm{OR}~\mathit{imm8}3
  1. 4 cycles for unprefixed or acc, [pi]
  2. 5 cycles for or acc, [pi] with prefix_a16 (the sequence prefix_a16; or acc, [pi] takes 6 cycles)