PHP                 PHP Push processor status on stack                PHP

  Operation:  P to Stack                                N V - B D I Z C
                                                        . . . . . . . .

  +----------------+-----------------------+---------+---------+----------+
  | Addressing Mode| Assembly Language Form| OP CODE |No. Bytes|No. Cycles|
  +----------------+-----------------------+---------+---------+----------+
  |  Implied/Stack |   PHP                 |   $08   |    1    |    3     |
  +----------------+-----------------------+---------+---------+----------+

What it does: Pulls the top byte off the stack and puts it into the Accumulator.

Major uses: To restore a number which was temporarily stored on top of the stack (with the PHA instruction). It is the opposite action of PHA. Note that PLA does affect the N and Z flags. Each PHA must be matched by a corresponding PLA if the stack is to correctly maintain RTS addresses, which is the main purpose of the stack.