The program counter is a part of a microprocessor that contains the memory address of the current machine language being executed. As each instruction is executed, the program counter increases the number of the address by one. In other words, its how the CPU knows where in a program it is when it is running one.

You can think of the program counter as the page numbers in a book. When you are done reading a page, you go on to reading the next page. The page number itself is increased by one.

The value stored in the program counter can be effected by other things, most notably instructions that tell it not to go on to the next instruction, but another one altogether.

Related Pages

• 6502
• Assembly Language
• CPU
• Memory Address