July 1, 2007 Leave a comment
This is part of a project to build a complete, functional, extremely basic microcontroller. It is built using multimedia logic.
This is a fully functional program counter (PC) that runs on a 1 second clock.
On page 1, there is a switch. If the switch is set to 1 then the PC increments by 1. If the switch is set to 0, the PC increments by an 8 bit amount that is specified by the 2 select buttons above the switch. Note that initially the switches are bothset to 0, meaning that if turned on this will not increment the PC.
On page 3, the switch indicates a reset switch, and before anything is done, this reset switch must be flipped to a 1 value. The 1 second clock is located on this page, and can easily be swapped out with a push button or oscilator.
On page 2, the 8 output led specifies where the PC is currently located.
Here is the source.