CLI                  CLI Clear interrupt disable bit                  CLI

  Operation: 0 -> I                                     N V - B D I Z C
                                                        . . . . . 0 . .

  +----------------+-----------------------+---------+---------+----------+
  | Addressing Mode| Assembly Language Form| OP CODE |No. Bytes|No. Cycles|
  +----------------+-----------------------+---------+---------+----------+
  |  Implied       |   CLI                 |   $58   |    1    |    2     |
  +----------------+-----------------------+---------+---------+----------+

What it does: Clears the interrupt-disable flag. All interrupts will therefore be serviced (including maskable ones).

Major uses: To restore normal interrupt routine processing following a temporary suspension of interrupts for the purpose of redirecting the interrupt vector. For more detail, see SEI.