Step 5 also begins the loading of the IR register, whose input is hooked to MBR's output. Step 6 turns off IR-LD, and also strobes PC-LD, allowing the new incremented value to be put back into the PC. The incrementer circuit of the PC register merely computes 1 plus the current value of the PC; it doesn't actually store it back into PC until the PC-LD wire goes high temporarily. Otherwise, the value of PC might be incremented several times.

Step 7 turns off PC-INCR and PC-LD, thereby ending the process of fetching the next instruction and pointing PC to the instruction after that.