Transfer control of the PC to a subroutine location

Leaves a return pointer on the stack high byte first.

Operation

PC + 2↓ [PC + 1] → PCL [PC + 2] → PCH

Table

JSR | Jump to Subroutine
==================================================

PC + 2↓                            N V - B D I Z C
[PC + 1] → PCL                    - - - - - - - -
[PC + 2] → PCH

addressing       assembler      opc  bytes  cycles
--------------------------------------------------
absolute         JSR $nnnn       20    3      6