1. 4-Bit Counter
Spencer Canavan

2. Description Synchronous Counter What it does
Clock pulses are sent to flip-flops at the same time
Becomes synchronized to the clock input/output instead of flip-flop outputs
What it does
When booted, the internal counter is 0
This number points to and “creates” first instruction
When instruction is completed, another can be set or it internally increments by 1
When it increments, it “points” to next instruction, after the one just completed
The counter works using flip-flops

4. Function in Processor
Takes input (instruction identifier) from Program ROM*
Input is sent to address register to “get” the instruction
Internal counter increases by 1
Will load next identifier associated with internal counter number if not given a “goto” instruction
Continues to do this until it reaches 15

5. Pinout
Vcc – high, ripple carry output – no connected, output Q a-d – connected to address + RAM, enable t – high, load – low, clear – high, clock – 555, inputs – program ROM, enable p – high, gnd - low