The PC-IR Module contains the 8-bit program counter and the 8-bit Instruction register. To make this design reasonably useful, I really needed an 8-bit program counter. This is implemented with two 74LVC193D 4-bit counters tied together. Because the design is intended to use some two cycle instructions, the program counter fed into two 74LVC173D 4-bit latches. This will be discussed in more detail later. I've included LEDs to indicate the current value of the program counter. The instruction register is also created using two 74LVC173D 4-bit latches. This allows the instruction set to use 8-bit wide instructions, which are 4-bit opcodes with 4-bit immediate values. I have also included LEDs to indicate the current 4-bit opcode. Because the system clock and reset are passed through this board to other boards, Schmitt Triggers have been added on those signals to deal with possible noise and current limitations.